Pub Date : 2024-09-05DOI: 10.1103/physrevmaterials.8.093401
Kejia Li, Chadawan Khamdang, Mengen Wang
is widely studied as an environmentally friendly Pb-free perovskite material for optoelectronic device applications. To further improve material and device performance, it is important to understand the surface structures of . We generate surface structures with various stoichiometries, perform density functional theory calculations to create phase diagrams of the (001), (110), and (100) surfaces, and determine the most stable surfaces under a wide range of Cs, Sn, and I chemical potentials. Under I-rich conditions, surfaces with Cs vacancies are stable, which lead to partially occupied surface states above the valence band maximum. Under I-poor conditions, we find the stoichiometric (100) surface to be stable under a wide region of the phase diagram, which does not have any surface states and can contribute to long charge-carrier lifetimes. Consequently, the I-poor (Sn-rich) conditions will be more beneficial to improve the device performance.
CsSnI3 作为一种用于光电器件应用的环保型无铅包晶材料，已被广泛研究。为了进一步提高材料和器件的性能，了解 CsSnI3 的表面结构非常重要。我们生成了具有各种化学计量的表面结构，进行了密度泛函理论计算，绘制了 CsSnI3 (001)、(110) 和 (100) 表面的相图，并确定了在各种 Cs、Sn 和 I 化学势下最稳定的表面。在 I 丰富的条件下，具有铯空位的表面是稳定的，这会导致价带最大值以上的部分占据表面态。在 I 贫乏的条件下，我们发现化学计量（100）表面在相图的很宽区域内是稳定的，它没有任何表面态，可导致较长的电荷载流子寿命。因此，贫离子（富含锡）条件更有利于提高器件性能。
{"title":"Surface phase diagram of CsSnI3 from first-principles calculations","authors":"Kejia Li, Chadawan Khamdang, Mengen Wang","doi":"10.1103/physrevmaterials.8.093401","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.093401","url":null,"abstract":"<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>CsSnI</mi><mn>3</mn></msub></math> is widely studied as an environmentally friendly Pb-free perovskite material for optoelectronic device applications. To further improve material and device performance, it is important to understand the surface structures of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>CsSnI</mi><mn>3</mn></msub></math>. We generate surface structures with various stoichiometries, perform density functional theory calculations to create phase diagrams of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>CsSnI</mi><mn>3</mn></msub></math> (001), (110), and (100) surfaces, and determine the most stable surfaces under a wide range of Cs, Sn, and I chemical potentials. Under I-rich conditions, surfaces with Cs vacancies are stable, which lead to partially occupied surface states above the valence band maximum. Under I-poor conditions, we find the stoichiometric (100) surface to be stable under a wide region of the phase diagram, which does not have any surface states and can contribute to long charge-carrier lifetimes. Consequently, the I-poor (Sn-rich) conditions will be more beneficial to improve the device performance.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-03DOI: 10.1103/physrevmaterials.8.094201
Xiao Zhang, Ning Mao, Oleg Janson, Jeroen van den Brink, Rajyavardhan Ray
The recently synthesized ternary quasi-2D material is a bulk Weyl semimetal with an intrinsically layered structure, which poses the question of how the topology of its electronic structure depends on layer separations. Experimentally, these separations may be changed for instance by intercalation of the bulk, or by exfoliation, to reach monolayer or few-layer structures. Here, we show that in the monolayer limit a quantum spin Hall insulator (QSHI) state emerges, employing density functional calculations as well as a minimal four-orbital tight-binding model that we develop. Even for weak spin-orbit couplings the QSHI is present, which has an interesting edge state that features Rashba-split bands with quadratic band minima. Further, we find that a weak topological insulator (WTI) manifests in the bilayer system due to sizable intralayer hopping, contrary to the common lore that only weak interlayer interactions between stacked QSHIs lead to WTIs. Stacked bilayers give rise to a phase diagram as a function of the interlayer separation that comprises a Weyl semimetal, WTI, and normal insulator (NI) phases. These insights on the evolution of topology with dimensions can be transferred to the family of layered ternary transition metal tellurides.
{"title":"Layer dependent topological phases and transitions in TaRhTe4: From monolayer and bilayer to bulk","authors":"Xiao Zhang, Ning Mao, Oleg Janson, Jeroen van den Brink, Rajyavardhan Ray","doi":"10.1103/physrevmaterials.8.094201","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.094201","url":null,"abstract":"The recently synthesized ternary quasi-2D material <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>TaRhTe</mi><mn>4</mn></msub></math> is a bulk Weyl semimetal with an intrinsically layered structure, which poses the question of how the topology of its electronic structure depends on layer separations. Experimentally, these separations may be changed for instance by intercalation of the bulk, or by exfoliation, to reach monolayer or few-layer structures. Here, we show that in the monolayer limit a quantum spin Hall insulator (QSHI) state emerges, employing density functional calculations as well as a minimal four-orbital tight-binding model that we develop. Even for weak spin-orbit couplings the QSHI is present, which has an interesting edge state that features Rashba-split bands with quadratic band minima. Further, we find that a weak topological insulator (WTI) manifests in the bilayer system due to sizable intralayer hopping, contrary to the common lore that only weak interlayer interactions between stacked QSHIs lead to WTIs. Stacked bilayers give rise to a phase diagram as a function of the interlayer separation that comprises a Weyl semimetal, WTI, and normal insulator (NI) phases. These insights on the evolution of topology with dimensions can be transferred to the family of layered ternary transition metal tellurides.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Spinel oxide () is an attractive catalyst for oxygen evolution reaction (OER) due to its rich redox reactions and unique electronic structure. However, the electrocatalytic OER performance of has always been limited by the low specific surface area and poor intrinsic conductivity of . Cationic doping is an effective method in modulating the electrocatalytic activity at the atomic level to improve the conductivity and activity. Herein, a series of Fe-doped electrocatalysts were successfully prepared using a simple solvothermal method. Impressively, Fe-doped delivers an attractive small overpotential of 341 mV at and a Tafel slope of compared to . The x-ray photoelectron spectroscopy and the density functional theory calculations reveal that Fe dopants can regulate the electronic structure of Ni sites by donating electrons to Co atoms, which leads to an increased ratio and a reduced adsorption strength of oxygen intermediates at Ni sites, thus facilitating the conversion of *OH to *O. This work provides an effective approach to enhancing the electrocatalytic activities of non-noble-metal-based catalysts.
尖晶石氧化物（NiCo2O4）具有丰富的氧化还原反应和独特的电子结构，是一种极具吸引力的氧进化反应催化剂。然而，由于镍钴氧化物的比表面积低、内在电导率差，其电催化 OER 的性能一直受到限制。阳离子掺杂是在原子水平上调节电催化活性以提高电导率和活性的有效方法。本文采用简单的溶热法成功制备了一系列掺杂 Fe 的 NiCo2O4 电催化剂。令人印象深刻的是，与镍钴氧化物相比，掺杂铁的镍钴氧化物在 10mAcm-2 条件下具有 341 mV 的极小过电位和 74mVdec-1 的塔菲尔斜率。X 射线光电子能谱和密度泛函理论计算显示，掺杂铁元素可以通过向 Co 原子捐献电子来调节 Ni 位点的电子结构，从而导致 Ni3+ 比率增加，氧中间产物在 Ni 位点的吸附强度降低，从而促进 *OH 向 *O 的转化。这项工作为提高非贵金属基催化剂的电催化活性提供了一种有效的方法。
{"title":"Optimizing the adsorption strength of oxygen intermediates on NiCo2O4 by Fe doping to improve the oxygen evolution reaction performance","authors":"Xilin Zhang, Rui Song, Yanyan Zhai, Rui Zheng, Shan Wang, Zhongjun Ma, Zongxian Yang","doi":"10.1103/physrevmaterials.8.095801","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.095801","url":null,"abstract":"Spinel oxide (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiC</mi><msub><mi mathvariant=\"normal\">o</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>4</mn></msub></mrow></math>) is an attractive catalyst for oxygen evolution reaction (OER) due to its rich redox reactions and unique electronic structure. However, the electrocatalytic OER performance of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiC</mi><msub><mi mathvariant=\"normal\">o</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>4</mn></msub></mrow></math> has always been limited by the low specific surface area and poor intrinsic conductivity of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiC</mi><msub><mi mathvariant=\"normal\">o</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>4</mn></msub></mrow></math>. Cationic doping is an effective method in modulating the electrocatalytic activity at the atomic level to improve the conductivity and activity. Herein, a series of Fe-doped <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiC</mi><msub><mi mathvariant=\"normal\">o</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>4</mn></msub></mrow></math> electrocatalysts were successfully prepared using a simple solvothermal method. Impressively, Fe-doped <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiC</mi><msub><mi mathvariant=\"normal\">o</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>4</mn></msub></mrow></math> delivers an attractive small overpotential of 341 mV at <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>10</mn><mspace width=\"0.28em\"></mspace><mi>mA</mi><mspace width=\"0.16em\"></mspace><mi mathvariant=\"normal\">c</mi><msup><mrow><mi mathvariant=\"normal\">m</mi></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup></mrow></math> and a Tafel slope of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>74</mn><mspace width=\"0.28em\"></mspace><mi>mV</mi><mspace width=\"0.16em\"></mspace><mi>de</mi><msup><mrow><mi mathvariant=\"normal\">c</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math> compared to <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiC</mi><msub><mi mathvariant=\"normal\">o</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>4</mn></msub></mrow></math>. The x-ray photoelectron spectroscopy and the density functional theory calculations reveal that Fe dopants can regulate the electronic structure of Ni sites by donating electrons to Co atoms, which leads to an increased <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi mathvariant=\"normal\">N</mi><msup><mrow><mi mathvariant=\"normal\">i</mi></mrow><mrow><mn>3</mn><mo>+</mo></mrow></msup></mrow></math> ratio and a reduced adsorption strength of oxygen intermediates at Ni sites, thus facilitating the conversion of *OH to *O. This work provides an effective approach to enhancing the electrocatalytic activities of non-noble-metal-based catalysts.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-03DOI: 10.1103/physrevmaterials.8.094401
Stephan Erdmann, Halil İbrahim Sözen, Francois Guillou, Hargen Yibole, Thorsten Klüner
<math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>Fe</mi><mn>2</mn></msub><mi mathvariant="normal">P</mi></mrow></math>-based magnets are known for their significant magnetic properties, making them useful in various technological applications. The aim of this study was to investigate the effects of Si and Co substitution on the physical and magnetic properties of the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>Fe</mi><mn>2</mn></msub><mi mathvariant="normal">P</mi></mrow></math> compounds. In order to have a systematic understanding we have performed combined <i>ab initio</i> calculations and a set of experiments. Particular emphasis was placed on the study of preferential substitution sites, lattice constants, magnetic moments, and the Curie temperature (<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>T</mi><mi>C</mi></msub></math>), which was further explored by considering the exchange interaction energies <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>J</mi><mrow><mi>i</mi><mi>j</mi></mrow></msub></math>. Satisfactory agreement was observed between theoretical calculations and the predicted phase transition from the hexagonal to the body-centered-orthorhombic (BCO) crystal structure as a function of temperature. Theoretical calculations reveal that the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mn>2</mn><mi>c</mi></mrow></math> position is the preferred site for Si, while Co is expected to occupy the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mn>3</mn><mi>f</mi></mrow></math> sites. Theoretical analysis of the magnetic moments shows an increase up to <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mn>3.64</mn><mspace width="0.16em"></mspace><msub><mi>μ</mi><mi>B</mi></msub><mo>/</mo><mrow><mi mathvariant="normal">f</mi><mo>.</mo><mi mathvariant="normal">u</mi><mo>.</mo></mrow></mrow></math> for <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>x</mi></mrow></math> = 0.5 Si, which agrees with the experimental values of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mn>3.16</mn><mspace width="0.16em"></mspace><msub><mi>μ</mi><mi>B</mi></msub><mo>/</mo><mrow><mi mathvariant="normal">f</mi><mo>.</mo><mi mathvariant="normal">u</mi><mo>.</mo></mrow></mrow></math> Co substitution in <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>Fe</mi><mrow><mn>2</mn><mo>−</mo><mi>y</mi></mrow></msub><msub><mi>Co</mi><mi>y</mi></msub><msub><mi mathvariant="normal">P</mi><mrow><mn>0.84</mn></mrow></msub><msub><mi>Si</mi><mrow><mn>0.16</mn></mrow></msub></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>Fe</mi><mrow><mn>2</mn><mo>−</mo><mi>y</mi></mrow></msub><msub><mi>Co</mi><mi>y</mi></msub><msub><mi mathvariant="normal">P</mi><mrow><mn>0.59</mn></mrow></msub><msub><mi>Si</mi><mrow><mn>0.41</mn></mrow></msub></mrow></math> resulted in a decrease in magnetic moments and consequently in other magnetic prope
众所周知，Fe2P 基磁体具有显著的磁性能，因此在各种技术应用中都非常有用。本研究旨在探讨硅和钴的替代对 Fe2P 化合物物理和磁性能的影响。为了对其有一个系统的了解，我们结合了 ab initio 计算和一系列实验。重点研究了优先取代位点、晶格常数、磁矩和居里温度 (TC)，并通过考虑交换相互作用能 Jij 进一步探讨了居里温度。理论计算结果与预测的从六方晶体结构到体心正方体（BCO）晶体结构的相变随温度变化的函数之间存在令人满意的一致性。理论计算显示，2c 位是硅的首选位置，而 Co 预计会占据 3f 位。在 Fe2-yCoyP0.84Si0.16 和 Fe2-yCoyP0.59Si0.41 中取代 Co 会导致磁矩减小，从而降低其他磁性能。在居里温度方面，根据硅浓度的不同，发现了三种不同的趋势。3f-3f 层内交换相互作用能量对 Si 的依赖性被认为是这些趋势的原因，并被推断为低浓度 Si 时 TC 增加、中浓度 Si 时 TC 不变以及高浓度 Si 时 TC 降低的原因。
{"title":"Theoretical and experimental investigations on Fe2P-type magnets: Effects of Si and Co substitution on physical and magnetic properties","authors":"Stephan Erdmann, Halil İbrahim Sözen, Francois Guillou, Hargen Yibole, Thorsten Klüner","doi":"10.1103/physrevmaterials.8.094401","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.094401","url":null,"abstract":"<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Fe</mi><mn>2</mn></msub><mi mathvariant=\"normal\">P</mi></mrow></math>-based magnets are known for their significant magnetic properties, making them useful in various technological applications. The aim of this study was to investigate the effects of Si and Co substitution on the physical and magnetic properties of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Fe</mi><mn>2</mn></msub><mi mathvariant=\"normal\">P</mi></mrow></math> compounds. In order to have a systematic understanding we have performed combined <i>ab initio</i> calculations and a set of experiments. Particular emphasis was placed on the study of preferential substitution sites, lattice constants, magnetic moments, and the Curie temperature (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>T</mi><mi>C</mi></msub></math>), which was further explored by considering the exchange interaction energies <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>J</mi><mrow><mi>i</mi><mi>j</mi></mrow></msub></math>. Satisfactory agreement was observed between theoretical calculations and the predicted phase transition from the hexagonal to the body-centered-orthorhombic (BCO) crystal structure as a function of temperature. Theoretical calculations reveal that the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>2</mn><mi>c</mi></mrow></math> position is the preferred site for Si, while Co is expected to occupy the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>3</mn><mi>f</mi></mrow></math> sites. Theoretical analysis of the magnetic moments shows an increase up to <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>3.64</mn><mspace width=\"0.16em\"></mspace><msub><mi>μ</mi><mi>B</mi></msub><mo>/</mo><mrow><mi mathvariant=\"normal\">f</mi><mo>.</mo><mi mathvariant=\"normal\">u</mi><mo>.</mo></mrow></mrow></math> for <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>x</mi></mrow></math> = 0.5 Si, which agrees with the experimental values of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>3.16</mn><mspace width=\"0.16em\"></mspace><msub><mi>μ</mi><mi>B</mi></msub><mo>/</mo><mrow><mi mathvariant=\"normal\">f</mi><mo>.</mo><mi mathvariant=\"normal\">u</mi><mo>.</mo></mrow></mrow></math> Co substitution in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Fe</mi><mrow><mn>2</mn><mo>−</mo><mi>y</mi></mrow></msub><msub><mi>Co</mi><mi>y</mi></msub><msub><mi mathvariant=\"normal\">P</mi><mrow><mn>0.84</mn></mrow></msub><msub><mi>Si</mi><mrow><mn>0.16</mn></mrow></msub></mrow></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Fe</mi><mrow><mn>2</mn><mo>−</mo><mi>y</mi></mrow></msub><msub><mi>Co</mi><mi>y</mi></msub><msub><mi mathvariant=\"normal\">P</mi><mrow><mn>0.59</mn></mrow></msub><msub><mi>Si</mi><mrow><mn>0.41</mn></mrow></msub></mrow></math> resulted in a decrease in magnetic moments and consequently in other magnetic prope","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High thermoelectric properties are associated with the phonon-glass electron-crystal paradigm. Conventional wisdom suggests that the optimal bandgap of semiconductor to achieve the largest power factor should be between 6 and . To address challenges related to the bipolar effect and temperature limitations, we present findings on Zintl-type , which demonstrates an exceptionally low lattice thermal conductivity of 0.30 W at 300 K. The achieved figure of merit () for , featuring a 2.40 eV bandgap, reaches a value of 1.53 for -type semiconductor. This remarkable is attributed to the existence of extended antibonding states [Ag-I] in the valence band. Furthermore, the bonding hierarchy, influencing phonon anharmonicity, and coordination bonds, facilitating electron transfer between the ligand and the central metal ion, significantly contribute to the electronic transport. This finding serves as a promising avenue for the development of high materials with wide bandgaps at elevated temperatures.
高热电特性与声子玻璃电子晶体范例有关。传统观点认为，要达到最大功率因数，半导体的最佳带隙应在 6 到 10κBT 之间。为了应对与双极效应和温度限制有关的挑战，我们展示了对 Zintl 型 TlAgI2 的研究结果，它在 300 K 时的晶格热导率非常低，仅为 0.30 W m-1K-1。这一显著的 ZT 值归因于价带中存在扩展的反键态 [Ag-I]。此外，影响声子非谐波性的成键层次和促进配体与中心金属离子间电子转移的配位键也对电子传输起了重要作用。这一发现为在高温下开发具有宽带隙的高 ZT 材料提供了一个很好的途径。
{"title":"Bonding hierarchy and coordination interaction leading to high thermoelectricity in wide bandgap TlAgI2","authors":"Xiaoying Wang, Mengyang Li, Minxuan Feng, Xuejie Li, Yuzhou Hao, Wen Shi, Jiangang He, Xiangdong Ding, Zhibin Gao","doi":"10.1103/physrevmaterials.8.094601","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.094601","url":null,"abstract":"High thermoelectric properties are associated with the phonon-glass electron-crystal paradigm. Conventional wisdom suggests that the optimal bandgap of semiconductor to achieve the largest power factor should be between 6 and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>10</mn><msub><mi>κ</mi><mi>B</mi></msub><mi>T</mi></mrow></math>. To address challenges related to the bipolar effect and temperature limitations, we present findings on Zintl-type <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>TlAgI</mi><mn>2</mn></msub></math>, which demonstrates an exceptionally low lattice thermal conductivity of 0.30 W <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msup><mrow><mi mathvariant=\"normal\">m</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mspace width=\"4pt\"></mspace><msup><mrow><mi mathvariant=\"normal\">K</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math> at 300 K. The achieved figure of merit (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Z</mi><mi>T</mi></mrow></math>) for <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>TlAgI</mi><mn>2</mn></msub></math>, featuring a 2.40 eV bandgap, reaches a value of 1.53 for <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>p</mi></math>-type semiconductor. This remarkable <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Z</mi><mi>T</mi></mrow></math> is attributed to the existence of extended antibonding states [Ag-I] in the valence band. Furthermore, the bonding hierarchy, influencing phonon anharmonicity, and coordination bonds, facilitating electron transfer between the ligand and the central metal ion, significantly contribute to the electronic transport. This finding serves as a promising avenue for the development of high <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Z</mi><mi>T</mi></mrow></math> materials with wide bandgaps at elevated temperatures.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We investigate the crystal and electronic structures as well as magnetic properties of ilmenite-type , which has attracted research interest as an = 1 honeycomb lattice magnet. Ilmenite-type samples were synthesized under high-pressure and high-temperature conditions. Synchrotron x-ray diffraction and Rietveld refinement results demonstrated that underwent a continuous structural phase transition from the triclinic () phase to the rhombohedral () phase at 450 K. This transition is concomitant with the decomposition of the V-V dimers formed by the tetravalent V ions. X-ray absorption spectroscopy measurements confirmed that the Ni and V ions were divalent and tetravalent, respectively. Magnetic and specific heat measurements revealed that underwent an antiferromagnetic transition at 140 K, and a zigzag-type magnetic order with magnetic propagation vector was observed by neutron diffraction measurements.
我们研究了钛铁矿型 NiVO3 的晶体和电子结构以及磁性能，它作为一种 S = 1 蜂窝晶格磁体引起了研究兴趣。钛铁矿型 NiVO3 样品是在高压和高温条件下合成的。同步辐射 X 射线衍射和里特维尔德细化结果表明，NiVO3 在 450 K 时经历了从三菱（P1¯）相到斜方体（R3¯）相的连续结构相变。X 射线吸收光谱测量证实，镍离子和 V 离子分别为二价和四价。磁性和比热测量结果表明，NiVO3 在 140 K 时发生了反铁磁转变，中子衍射测量观察到磁传播矢量 k=(0,1/2,0) 的人字形磁序。
{"title":"Continuous structural phase transition and antiferromagnetic order in ilmenite-type NiVO3","authors":"Hajime Yamamoto, Osamu Ikeda, Takashi Honda, Kenta Kimura, Takuya Aoyama, Kenya Ohgushi, Akio Suzuki, Kenji Ishii, Daiju Matsumura, Takuya Tsuji, Shintaro Kobayashi, Shogo Kawaguchi, Matteo d’Astuto, Tadashi Abukawa","doi":"10.1103/physrevmaterials.8.094402","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.094402","url":null,"abstract":"We investigate the crystal and electronic structures as well as magnetic properties of ilmenite-type <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiV</mi><msub><mi mathvariant=\"normal\">O</mi><mn>3</mn></msub></mrow></math>, which has attracted research interest as an <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>S</mi></mrow></math> = 1 honeycomb lattice magnet. Ilmenite-type <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiV</mi><msub><mi mathvariant=\"normal\">O</mi><mn>3</mn></msub></mrow></math> samples were synthesized under high-pressure and high-temperature conditions. Synchrotron x-ray diffraction and Rietveld refinement results demonstrated that <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiV</mi><msub><mi mathvariant=\"normal\">O</mi><mn>3</mn></msub></mrow></math> underwent a continuous structural phase transition from the triclinic (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>P</mi></mrow><mover accent=\"true\"><mn>1</mn><mo>¯</mo></mover></math>) phase to the rhombohedral (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>R</mi></mrow><mover accent=\"true\"><mn>3</mn><mo>¯</mo></mover></math>) phase at 450 K. This transition is concomitant with the decomposition of the V-V dimers formed by the tetravalent V ions. X-ray absorption spectroscopy measurements confirmed that the Ni and V ions were divalent and tetravalent, respectively. Magnetic and specific heat measurements revealed that <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NiV</mi><msub><mi mathvariant=\"normal\">O</mi><mn>3</mn></msub></mrow></math> underwent an antiferromagnetic transition at 140 K, and a zigzag-type magnetic order with magnetic propagation vector <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>k</mi><mo>=</mo><mo>(</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>/</mo><mn>2</mn><mo>,</mo><mn>0</mn><mo>)</mo></mrow></math> was observed by neutron diffraction measurements.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-30DOI: 10.1103/physrevmaterials.8.084413
Mebatsion S. Gebre, Rebecca K. Banner, Kisung Kang, Kejian Qu, Huibo Cao, André Schleife, Daniel P. Shoemaker
Multiple recent studies have identified the metallic antiferromagnet <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> to be a candidate for spintronic applications due to apparent in-plane anisotropy, preserved magnetic properties above room temperature, and current-induced Néel vector switching. Crystal growth is complicated by the fact that <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> melts incongruently. We present a bismuth flux method to grow millimeter-scale bulk single crystals of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> in order to examine the intrinsic anisotropic electrical and magnetic properties. Flux quenching experiments reveal that the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> crystals precipitate below <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mn>550</mn><msup><mspace width="0.16em"></mspace><mo>∘</mo></msup><mi mathvariant="normal">C</mi></mrow></math>, about <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mn>100</mn><msup><mspace width="0.16em"></mspace><mo>∘</mo></msup><mi mathvariant="normal">C</mi></mrow></math> below the decomposition temperature of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math>. Bulk <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> crystals have a room-temperature resistivity of 16–19 <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>µ</mi><mi mathvariant="normal">Ω</mi><mspace width="0.16em"></mspace><mi>cm</mi></mrow></math> and a residual resistivity ratio of 41. <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> crystals have a dimensionless susceptibility on the order of <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math> (SI units), comparable to calculated and experimental reports on powder samples. Single-crystal neutron diffraction confirms the in-plane magnetic structure. The tetragonal symmetry of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> constrains the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>a</mi><mi>b</mi></mrow></math>-plane magnetic susceptibility to be constant, meaning that <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>χ</mi><mn>100</mn></msub><mo>=</mo><msub><mi>χ</mi><mn>110</mn></msub></mrow></math> in the low-field limit, below any spin-flop transition. We find that three measured magnetic susceptibilities <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>χ</mi><mn>100</mn></msub><mo>,</mo><mo> </mo><msub
{"title":"Magnetic anisotropy in single-crystalline antiferromagnetic Mn2Au","authors":"Mebatsion S. Gebre, Rebecca K. Banner, Kisung Kang, Kejian Qu, Huibo Cao, André Schleife, Daniel P. Shoemaker","doi":"10.1103/physrevmaterials.8.084413","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.084413","url":null,"abstract":"Multiple recent studies have identified the metallic antiferromagnet <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> to be a candidate for spintronic applications due to apparent in-plane anisotropy, preserved magnetic properties above room temperature, and current-induced Néel vector switching. Crystal growth is complicated by the fact that <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> melts incongruently. We present a bismuth flux method to grow millimeter-scale bulk single crystals of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> in order to examine the intrinsic anisotropic electrical and magnetic properties. Flux quenching experiments reveal that the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> crystals precipitate below <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>550</mn><msup><mspace width=\"0.16em\"></mspace><mo>∘</mo></msup><mi mathvariant=\"normal\">C</mi></mrow></math>, about <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>100</mn><msup><mspace width=\"0.16em\"></mspace><mo>∘</mo></msup><mi mathvariant=\"normal\">C</mi></mrow></math> below the decomposition temperature of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math>. Bulk <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> crystals have a room-temperature resistivity of 16–19 <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>µ</mi><mi mathvariant=\"normal\">Ω</mi><mspace width=\"0.16em\"></mspace><mi>cm</mi></mrow></math> and a residual resistivity ratio of 41. <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> crystals have a dimensionless susceptibility on the order of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math> (SI units), comparable to calculated and experimental reports on powder samples. Single-crystal neutron diffraction confirms the in-plane magnetic structure. The tetragonal symmetry of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> constrains the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>a</mi><mi>b</mi></mrow></math>-plane magnetic susceptibility to be constant, meaning that <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>χ</mi><mn>100</mn></msub><mo>=</mo><msub><mi>χ</mi><mn>110</mn></msub></mrow></math> in the low-field limit, below any spin-flop transition. We find that three measured magnetic susceptibilities <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>χ</mi><mn>100</mn></msub><mo>,</mo><mo> </mo><msub","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-29DOI: 10.1103/physrevmaterials.8.085203
Shunshun Liu, Victor K. Champagne, III, David R. Clarke, Prasanna V. Balachandran
Yttria-stabilized zirconia (YSZ) coatings have been developed for high temperature energy applications including gas turbines. The objective of this work is to understand how aliovalent Fe substitution affects the optical absorption spectrum of the host YSZ and systems in the ultraviolet–visible–near infrared wavelength range (from 245 to 2500 nm) using both experimental and computational techniques. In the Fe-substituted system, phase-pure (% purity) samples were synthesized in the monoclinic crystal structure, whereas Fe substitution in YSZ resulted in a two-phase mixture of coexisting tetragonal and monoclinic phases. Optical property characterization performed at room temperature revealed two broad absorption bands in both systems: one centered around 1000 nm and the other centered around 500 nm. Tauc plot analysis of the optical absorption data showed that as the Fe concentration increases, the optical band gaps of both materials systems decrease. Many-body perturbation theory methods, based on and the Bethe-Salpeter equation, were used to computationally model the optical absorption spectrum as a function of Fe substitution in the tetragonal and monoclinic crystal structures of YSZ and . Supercells were constructed and several Fe- and/or Y-atom configurations were explored in Zr sites. Charge compensating O vacancies were introduced to maintain electrical neutrality. The computations reveal that the observed optical excitations centered around 1000 nm likely have an excitonic character due to defect states, whose origin is traced to the electronic transitions between and orbitals. Intriguingly, both the tetragonal and monoclinic crystal structures appear to support local polyhedral distortions that promote excitations in the 1000 nm wavelength region. The excitation centered around 500 nm is attributed to the optical band gap of these materials. The outcomes of this work shed light on the radiative properties of Fe-substituted YSZ with implications in thermal barrier coating composition design.
{"title":"Optical absorption study of iron-substituted zirconia and yttria-stabilized zirconia using experimental measurements and many-body perturbation theory","authors":"Shunshun Liu, Victor K. Champagne, III, David R. Clarke, Prasanna V. Balachandran","doi":"10.1103/physrevmaterials.8.085203","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.085203","url":null,"abstract":"Yttria-stabilized zirconia (YSZ) coatings have been developed for high temperature energy applications including gas turbines. The objective of this work is to understand how aliovalent Fe substitution affects the optical absorption spectrum of the host YSZ and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>ZrO</mi><mn>2</mn></msub></math> systems in the ultraviolet–visible–near infrared wavelength range (from 245 to 2500 nm) using both experimental and computational techniques. In the Fe-substituted <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>ZrO</mi><mn>2</mn></msub></math> system, phase-pure (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mo>></mo><mn>99</mn></math>% purity) samples were synthesized in the monoclinic crystal structure, whereas Fe substitution in YSZ resulted in a two-phase mixture of coexisting tetragonal and monoclinic phases. Optical property characterization performed at room temperature revealed two broad absorption bands in both systems: one centered around 1000 nm and the other centered around 500 nm. Tauc plot analysis of the optical absorption data showed that as the Fe concentration increases, the optical band gaps of both materials systems decrease. Many-body perturbation theory methods, based on <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>G</mi><mn>0</mn></msub><msub><mi>W</mi><mn>0</mn></msub></mrow></math> and the Bethe-Salpeter equation, were used to computationally model the optical absorption spectrum as a function of Fe substitution in the tetragonal and monoclinic crystal structures of YSZ and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>ZrO</mi><mn>2</mn></msub></math>. Supercells were constructed and several Fe- and/or Y-atom configurations were explored in Zr sites. Charge compensating O vacancies were introduced to maintain electrical neutrality. The computations reveal that the observed optical excitations centered around 1000 nm likely have an excitonic character due to defect states, whose origin is traced to the electronic transitions between <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Fe</mi><mtext>−</mtext><mn>3</mn><mi>d</mi></mrow></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Fe</mi><mtext>−</mtext><mn>3</mn><mi>d</mi></mrow></math> orbitals. Intriguingly, both the tetragonal and monoclinic crystal structures appear to support local polyhedral distortions that promote excitations in the 1000 nm wavelength region. The excitation centered around 500 nm is attributed to the optical band gap of these materials. The outcomes of this work shed light on the radiative properties of Fe-substituted YSZ with implications in thermal barrier coating composition design.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-29DOI: 10.1103/physrevmaterials.8.084412
Takahiro Urata, Wataru Hattori, Hiroshi Ikuta
A newly identified magnetic phase called altermagnet is being actively studied because of its unprecedented spin-dependent phenomena. Among the candidate materials, CrSb has a particularly high ordering temperature and a large spin-splitting energy, but its transport properties have remained unexplored. In this study, we report the magnetotransport properties of CrSb measured on single crystals. We found that the Hall resistivity shows a nonlinear dependence on the magnetic field at low temperatures. From symmetry-based considerations, however, this behavior cannot be attributed to an anomalous Hall effect, but to a multicarrier effect. A multicarrier fitting to the in-plane conductivity tensor revealed the presence of carriers with high mobility in CrSb, which is an advantage for efficient spin current generation.
{"title":"High mobility charge transport in a multicarrier altermagnet CrSb","authors":"Takahiro Urata, Wataru Hattori, Hiroshi Ikuta","doi":"10.1103/physrevmaterials.8.084412","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.084412","url":null,"abstract":"A newly identified magnetic phase called altermagnet is being actively studied because of its unprecedented spin-dependent phenomena. Among the candidate materials, CrSb has a particularly high ordering temperature and a large spin-splitting energy, but its transport properties have remained unexplored. In this study, we report the magnetotransport properties of CrSb measured on single crystals. We found that the Hall resistivity shows a nonlinear dependence on the magnetic field at low temperatures. From symmetry-based considerations, however, this behavior cannot be attributed to an anomalous Hall effect, but to a multicarrier effect. A multicarrier fitting to the in-plane conductivity tensor revealed the presence of carriers with high mobility in CrSb, which is an advantage for efficient spin current generation.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recently reported remarkably high radiation tolerance of double-polymorphic structure brings this ultrawide-band-gap semiconductor to the frontiers of power electronics applications that are able to operate in challenging environments. Understanding the mechanism of radiation tolerance is crucial for further material modification and tailoring of the desired properties. In this study, we employ machine-learning-enhanced atomistic simulations to assess the stability of both the gallium () and oxygen () sublattices under various levels of damage. Our study uncovers the remarkable resilience and stability of the -sublattice, attributing this property to the strong tendency of recovery of the defects, especially within the more strongly disordered regions. Interestingly, we observe the opposite behavior of the defects that display enhanced stability in the same regions of increased disorder. Moreover, we observe that highly defective is able to transform into upon annealing due to preserved lattice organization of the sublattice. This result clearly manifests that the ultrahigh stability of the sublattice provides the backbone for the exceptional radiation tolerance of the double-polymorphic structure. These computational insights closely align with experimental observations, opening avenues for further exploration of polymorphism in and potentially in analogous polymorphic families spanning a broad range of diverse materials of complex polymorphic nature.
据最近报道，γ/β-Ga2O3 双多晶结构具有极高的辐射耐受性，这将这种超宽带隙半导体带入了能够在具有挑战性的环境中工作的电力电子应用领域的前沿。了解辐射耐受性的机理对于进一步改性材料和定制所需的性能至关重要。在本研究中，我们采用机器学习增强型原子模拟来评估镓（Ga）和氧（O）子晶格在不同程度的损伤下的稳定性。我们的研究揭示了-亚晶格非凡的恢复力和稳定性，并将这一特性归因于氧缺陷的强烈恢复趋势，尤其是在较强无序区域内。有趣的是，我们观察到 Ga 缺陷的行为恰恰相反，它们在无序度增加的相同区域显示出更强的稳定性。此外，我们还观察到，由于 O 子晶格的晶格组织得以保留，高度缺陷的 β-Ga2O3 能够在退火后转变为 γ-Ga2O3。这一结果清楚地表明，O 亚晶格的超高稳定性为 γ/β 双多晶结构提供了卓越的耐辐射性。这些计算见解与实验观察结果非常吻合，为进一步探索 Ga2O3 的多晶体性质以及潜在的类似多晶体家族开辟了道路，这些家族涵盖了具有复杂多晶体性质的各种材料。
{"title":"Ultrahigh stability of oxygen sublattice in β−Ga2O3","authors":"Ru He, Junlei Zhao, Jesper Byggmästar, Huan He, Flyura Djurabekova","doi":"10.1103/physrevmaterials.8.084601","DOIUrl":"https://doi.org/10.1103/physrevmaterials.8.084601","url":null,"abstract":"Recently reported remarkably high radiation tolerance of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>γ</mi><mo>/</mo><mi>β</mi><mtext>−</mtext><msub><mi>Ga</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>3</mn></msub></mrow></math> double-polymorphic structure brings this ultrawide-band-gap semiconductor to the frontiers of power electronics applications that are able to operate in challenging environments. Understanding the mechanism of radiation tolerance is crucial for further material modification and tailoring of the desired properties. In this study, we employ machine-learning-enhanced atomistic simulations to assess the stability of both the gallium (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>Ga</mi></math>) and oxygen (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi mathvariant=\"normal\">O</mi></math>) sublattices under various levels of damage. Our study uncovers the remarkable resilience and stability of the -sublattice, attributing this property to the strong tendency of recovery of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi mathvariant=\"normal\">O</mi></math> defects, especially within the more strongly disordered regions. Interestingly, we observe the opposite behavior of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>Ga</mi></math> defects that display enhanced stability in the same regions of increased disorder. Moreover, we observe that highly defective <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>β</mi><mtext>−</mtext><msub><mi>Ga</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>3</mn></msub></mrow></math> is able to transform into <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>γ</mi><mtext>−</mtext><msub><mi>Ga</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>3</mn></msub></mrow></math> upon annealing due to preserved lattice organization of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi mathvariant=\"normal\">O</mi></math> sublattice. This result clearly manifests that the ultrahigh stability of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi mathvariant=\"normal\">O</mi></math> sublattice provides the backbone for the exceptional radiation tolerance of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>γ</mi><mo>/</mo><mi>β</mi></mrow></math> double-polymorphic structure. These computational insights closely align with experimental observations, opening avenues for further exploration of polymorphism in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Ga</mi><mn>2</mn></msub><msub><mi mathvariant=\"normal\">O</mi><mn>3</mn></msub></mrow></math> and potentially in analogous polymorphic families spanning a broad range of diverse materials of complex polymorphic nature.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：