This study extensively characterizes the out‐of‐plane stiffness and energy harvesting capabilities of a newly proposed anti‐trichiral hierarchical auxetic honeycomb structure, both mechanically and deformationally. By introducing a design concept based on the anti‐trichiral honeycomb (ATCH), a structure with superior out‐of‐plane load‐carrying capacity and excellent auxeticity is achieved. To validate the finite element model, compression simulations are conducted. Comparative investigations into the morphing characteristics and energy harvesting performance between the novel structure and the ATCH are performed. Additionally, the influence of various parameters on the comprehensive performance of the novel auxetic structure is explored. It has been found that the angle φ is most sensitive to the auxetic properties, while the ratio k significantly impacts energy absorption. This research advances the design of novel auxetic structures for potential applications in protective engineering.
本研究从机械和变形两方面广泛鉴定了一种新提出的反三螺旋分层辅助蜂窝结构的平面外刚度和能量收集能力。通过引入基于反三螺旋蜂窝（ATCH）的设计理念，该结构实现了卓越的平面外承载能力和出色的辅助性。为了验证有限元模型，我们进行了压缩模拟。对新型结构和 ATCH 的变形特性和能量收集性能进行了比较研究。此外，还探讨了各种参数对新型辅助结构综合性能的影响。研究发现，角度 φ 对辅助特性最为敏感，而比率 k 则对能量吸收有显著影响。这项研究推动了新型辅助结构的设计，有望在防护工程中得到应用。
{"title":"Out‐of‐Plane Dynamics of a Novel Auxetic Honeycomb with an Anti‐Trichiral Hierarchy","authors":"Xinlong Guang, Huilan Huang, Xiaolin Deng","doi":"10.1002/pssb.202400191","DOIUrl":"https://doi.org/10.1002/pssb.202400191","url":null,"abstract":"This study extensively characterizes the out‐of‐plane stiffness and energy harvesting capabilities of a newly proposed anti‐trichiral hierarchical auxetic honeycomb structure, both mechanically and deformationally. By introducing a design concept based on the anti‐trichiral honeycomb (ATCH), a structure with superior out‐of‐plane load‐carrying capacity and excellent auxeticity is achieved. To validate the finite element model, compression simulations are conducted. Comparative investigations into the morphing characteristics and energy harvesting performance between the novel structure and the ATCH are performed. Additionally, the influence of various parameters on the comprehensive performance of the novel auxetic structure is explored. It has been found that the angle φ is most sensitive to the auxetic properties, while the ratio k significantly impacts energy absorption. This research advances the design of novel auxetic structures for potential applications in protective engineering.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141273917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Silicon carbide (SiC), as a third‐generation semiconductor material, has attracted significant research attention. Various empirical potentials and machine learning potentials have been developed, but there are few comparative studies on phonon and thermal properties. Herein, the Tersoff and Vashishta empirical potentials, as well as the Bayesian force field constructed by the FLARE framework using principled Gaussian process uncertainties (FLARE BFF), for a comparative study, are selected. The phonon dispersion relation, phonon density of states, Grüneisen constants, and the average phonon‐weighted Grüneisen constants are calculated using different potentials, and it is found that the FLARE BFF potential has the highest accuracy with respect to the first‐principles calculations. Furthermore, the thermal conductivity using molecular dynamics simulation with different potentials is calculated. The calculation results using the FLARE BFF potential closely match the experimental reports at high temperature, but the longest computing time is required. This study can facilitate the understanding of thermal properties of SiC.
{"title":"Phonon and Thermal Properties of Silicon Carbide: A Comparison of Empirical and Machine Learning Potentials","authors":"Jian Zhang, Haochun Zhang, Yuan Zhang, Xikui Ma, Weifeng Li, Gang Zhang","doi":"10.1002/pssb.202400070","DOIUrl":"https://doi.org/10.1002/pssb.202400070","url":null,"abstract":"Silicon carbide (SiC), as a third‐generation semiconductor material, has attracted significant research attention. Various empirical potentials and machine learning potentials have been developed, but there are few comparative studies on phonon and thermal properties. Herein, the Tersoff and Vashishta empirical potentials, as well as the Bayesian force field constructed by the FLARE framework using principled Gaussian process uncertainties (FLARE BFF), for a comparative study, are selected. The phonon dispersion relation, phonon density of states, Grüneisen constants, and the average phonon‐weighted Grüneisen constants are calculated using different potentials, and it is found that the FLARE BFF potential has the highest accuracy with respect to the first‐principles calculations. Furthermore, the thermal conductivity using molecular dynamics simulation with different potentials is calculated. The calculation results using the FLARE BFF potential closely match the experimental reports at high temperature, but the longest computing time is required. This study can facilitate the understanding of thermal properties of SiC.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141273709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Kumar, Shilpa Tripathi, Pranesh Sengupta, S. N. Jha, Mangla Nand, Ayushi Trivedi, A. Sagdeo, Anupam Sharma, M. Tiwari, Vasant G Sathe, A. Arya
Structural properties of Indian metamict single zircon crystals are studied by comparing their properties with those of synthetic zircon synthesized via solid‐state reaction method, which serves as the standard. X‐Ray diffraction (XRD) data reveal changes in lattice parameters and the presence of strain, metamictization, etc. It is found that the degree of crystallinity is ≈63.8% indicating the simultaneous presence of crystalline and disordered regions. These changes are likely due to the presence of several radioactive/nonradioactive elements. The presence of such elements is observed and the sample composition is analyzed through total reflection X‐Ray fluorescence. XRD crystallographic data are further utilized as input for analyzing X‐Ray absorption spectroscopy data recorded around Zr central absorbing atom. X‐Ray absorption near‐edge structure shows slight modification in the white line feature and some disorder compared to the synthetic one. Reduced coordination number observed from extended X‐Ray absorption fine structure suggests the presence of disorder in local structure. Micro‐Raman spectroscopy indicates that crystalline behavior varies across different locations, suggesting that the sample has undergone varying degrees of metamictization, confirming a nonuniform distribution of elements. The work documents and analyses structural evolution within isolated silica tetrahedron network in association of Zr4+ cation as a function of self‐irradiation and recovery over millions of years and correlating the same with optical properties.
通过将印度元锆石单晶体的结构特性与通过固态反应方法合成的合成锆石（作为标准）的结构特性进行比较，研究了印度元锆石单晶体的结构特性。X 射线衍射（XRD）数据揭示了晶格参数的变化以及应变、偏二甲化等现象的存在。研究发现，结晶度≈63.8%，表明同时存在结晶区和无序区。这些变化可能是由于多种放射性/非放射性元素的存在。通过全反射 X 射线荧光法观察了这些元素的存在并分析了样品成分。XRD 晶体学数据被进一步用作分析围绕 Zr 中心吸收原子记录的 X 射线吸收光谱数据的输入。与合成结构相比，X 射线吸收近缘结构显示出白线特征的轻微变化和一些无序。从扩展的 X 射线吸收精细结构中观察到的配位数减少表明局部结构中存在无序现象。显微拉曼光谱显示，不同位置的结晶行为各不相同，表明样品经历了不同程度的偏金属化，证实了元素的不均匀分布。这项工作记录并分析了与 Zr4+ 阳离子有关的孤立二氧化硅四面体网络的结构演变，它是数百万年来自我辐照和恢复的函数，并与光学特性相关联。
{"title":"Local Structure, Structural, Vibrational, and Optical Properties of Natural Zircon","authors":"Y. Kumar, Shilpa Tripathi, Pranesh Sengupta, S. N. Jha, Mangla Nand, Ayushi Trivedi, A. Sagdeo, Anupam Sharma, M. Tiwari, Vasant G Sathe, A. Arya","doi":"10.1002/pssb.202400032","DOIUrl":"https://doi.org/10.1002/pssb.202400032","url":null,"abstract":"Structural properties of Indian metamict single zircon crystals are studied by comparing their properties with those of synthetic zircon synthesized via solid‐state reaction method, which serves as the standard. X‐Ray diffraction (XRD) data reveal changes in lattice parameters and the presence of strain, metamictization, etc. It is found that the degree of crystallinity is ≈63.8% indicating the simultaneous presence of crystalline and disordered regions. These changes are likely due to the presence of several radioactive/nonradioactive elements. The presence of such elements is observed and the sample composition is analyzed through total reflection X‐Ray fluorescence. XRD crystallographic data are further utilized as input for analyzing X‐Ray absorption spectroscopy data recorded around Zr central absorbing atom. X‐Ray absorption near‐edge structure shows slight modification in the white line feature and some disorder compared to the synthetic one. Reduced coordination number observed from extended X‐Ray absorption fine structure suggests the presence of disorder in local structure. Micro‐Raman spectroscopy indicates that crystalline behavior varies across different locations, suggesting that the sample has undergone varying degrees of metamictization, confirming a nonuniform distribution of elements. The work documents and analyses structural evolution within isolated silica tetrahedron network in association of Zr4+ cation as a function of self‐irradiation and recovery over millions of years and correlating the same with optical properties.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141102132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Salima Boutiche, Xu He, Hania Djani, Eric Bousquet
Herein, from first‐principles calculations, the phase diagram of the low‐spin (LS) state of BiCoO3 is scrutinized. The phonon‐dispersion curves of the cubic phase are analyzed to identify all the possible unstable modes and assessed the energy gain of the resulted distorted phases. In the findings, the presence of similar phases is revealed in both LS and high‐spin (HS) states, including ferroelectric and octahedra rotations distortions. However, the relative energy ordering of these phases differs significantly between the two states. Notably, the energy gain from mode condensation is considerably less pronounced in the LS case compared to HS state. Furthermore, it is identified that the common Pnma phase is the ground state of the LS state of BiCoC3, closely followed by the Imma octahedra rotation phase and the R3c ferroelectric phase, hence, different from the P4mm ferroelectric ground state of the HS state.
本文通过第一原理计算，仔细研究了BiCoO3的低自旋（LS）态相图。通过分析立方相的声子色散曲线，确定了所有可能的不稳定模式，并评估了由此产生的扭曲相的能量增益。研究结果表明，在 LS 和高自旋（HS）状态下都存在类似的相，包括铁电和八面体旋转变形。然而，这两种状态下这些相的相对能量排序有很大不同。值得注意的是，与 HS 状态相比，LS 状态下模式凝聚产生的能量增益要小得多。此外，研究还发现共同的 Pnma 相是 BiCoC3 LS 状态的基态，紧随其后的是 Imma 八面体旋转相和 R3c 铁电相，因此与 HS 状态的 P4mm 铁电基态不同。
{"title":"First‐Principles Investigations of the Structural Phases of Low‐Spin State of BiCoO3","authors":"Salima Boutiche, Xu He, Hania Djani, Eric Bousquet","doi":"10.1002/pssb.202400131","DOIUrl":"https://doi.org/10.1002/pssb.202400131","url":null,"abstract":"Herein, from first‐principles calculations, the phase diagram of the low‐spin (LS) state of BiCoO3 is scrutinized. The phonon‐dispersion curves of the cubic phase are analyzed to identify all the possible unstable modes and assessed the energy gain of the resulted distorted phases. In the findings, the presence of similar phases is revealed in both LS and high‐spin (HS) states, including ferroelectric and octahedra rotations distortions. However, the relative energy ordering of these phases differs significantly between the two states. Notably, the energy gain from mode condensation is considerably less pronounced in the LS case compared to HS state. Furthermore, it is identified that the common Pnma phase is the ground state of the LS state of BiCoC3, closely followed by the Imma octahedra rotation phase and the R3c ferroelectric phase, hence, different from the P4mm ferroelectric ground state of the HS state.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141099779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tusar Subhra Sarkar, Soumya Sarkar, S. Bhattacharyya, P. S. Majumdar
This study analyzes thermoluminescence (TL) glow curves simulated in general order kinetics (GOK), one trap one recombination center (OTOR), and non‐interactive multi‐trap system (NMTS) models using various heating rates (VHR) method in linear heating scheme to extract the activation energy. A theoretical analysis to determine activation energy from TL curves using OTOR and NMTS models in an iterative manner, where the TL intensity is determined by using the Lambert‐W function, is proposed with its limitations. It is established that the activation energies in OTOR and NMTS models consist of the relevant GOK term and a respective correction term. Systematic analysis is carried out to study the improvement of the accuracy of activation energy derived from OTOR and NMTS model TL curves over the GOK model calculation. A quantitative analysis of the quasi‐equilibrium (QE) approximations is carried out for choosing appropriate system parameters. The validity of QE conditions are determined by studying variations of full width at half maximum as well as area under the curve as a function of heating rate. The present method is applied on some experimental data to estimate activation energies. This investigation reveals that the activation energy derived in VHR method has negligible dependence on the underlying theoretical models, i.e., the activation energy derived from GOK model calculation is significantly accurate for experimental scenario.
{"title":"A Study toward the Model Independence of Various Heating Rates Method in Thermoluminescence Glow Curve Analysis","authors":"Tusar Subhra Sarkar, Soumya Sarkar, S. Bhattacharyya, P. S. Majumdar","doi":"10.1002/pssb.202400157","DOIUrl":"https://doi.org/10.1002/pssb.202400157","url":null,"abstract":"This study analyzes thermoluminescence (TL) glow curves simulated in general order kinetics (GOK), one trap one recombination center (OTOR), and non‐interactive multi‐trap system (NMTS) models using various heating rates (VHR) method in linear heating scheme to extract the activation energy. A theoretical analysis to determine activation energy from TL curves using OTOR and NMTS models in an iterative manner, where the TL intensity is determined by using the Lambert‐W function, is proposed with its limitations. It is established that the activation energies in OTOR and NMTS models consist of the relevant GOK term and a respective correction term. Systematic analysis is carried out to study the improvement of the accuracy of activation energy derived from OTOR and NMTS model TL curves over the GOK model calculation. A quantitative analysis of the quasi‐equilibrium (QE) approximations is carried out for choosing appropriate system parameters. The validity of QE conditions are determined by studying variations of full width at half maximum as well as area under the curve as a function of heating rate. The present method is applied on some experimental data to estimate activation energies. This investigation reveals that the activation energy derived in VHR method has negligible dependence on the underlying theoretical models, i.e., the activation energy derived from GOK model calculation is significantly accurate for experimental scenario.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141101637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The crystal structures of zirconium diboride have been thoroughly explored up to 200 GPa by applying the particle‐swarm optimization technique in company with first‐principles calculations. The hexagonal ZrB2 with space group of P6/mmm is always stable in the pressure region of 0–200 GPa. Structurally, this structure consists of the intriguing regular ZrB12 hexagonal column and the planar hexagonal B ring unit. In addition, the stable AlB2–ZrB2 configuration is mechanically and dynamically stable as confirmed by the respective calculations of elastic constants and phonon dispersion curves. The hardness values exhibit a shrinking variation upon further compression, which mainly originates from the decreasing brittleness and degree of the directionality of the covalent bonds with the growing pressure. Interestingly, the analyses of the Poisson's ratio, density of states, electron location function and Bader charge substantiate that a combination of covalent and ionic characters exists in the AlB2–ZrB2 crystalline with the formidable covalent interaction in the BB bonds, and partially covalent and partially ionic interactions in the ZrB bonds. The hardness value for this phase unexpectedly reaches 45.41 GPa under ambient pressure, higher than the lower limit of superhard materials.
{"title":"First‐Principles Investigation on the Structural, Mechanical, and Bonding Properties of ZrB2 Under Different Pressures","authors":"Shu‐ying Kang, Xi‐long Guo, Yuan‐yuan Jin, Fang G Kuang, Chuan‐zhao Zhang","doi":"10.1002/pssb.202400189","DOIUrl":"https://doi.org/10.1002/pssb.202400189","url":null,"abstract":"The crystal structures of zirconium diboride have been thoroughly explored up to 200 GPa by applying the particle‐swarm optimization technique in company with first‐principles calculations. The hexagonal ZrB2 with space group of P6/mmm is always stable in the pressure region of 0–200 GPa. Structurally, this structure consists of the intriguing regular ZrB12 hexagonal column and the planar hexagonal B ring unit. In addition, the stable AlB2–ZrB2 configuration is mechanically and dynamically stable as confirmed by the respective calculations of elastic constants and phonon dispersion curves. The hardness values exhibit a shrinking variation upon further compression, which mainly originates from the decreasing brittleness and degree of the directionality of the covalent bonds with the growing pressure. Interestingly, the analyses of the Poisson's ratio, density of states, electron location function and Bader charge substantiate that a combination of covalent and ionic characters exists in the AlB2–ZrB2 crystalline with the formidable covalent interaction in the BB bonds, and partially covalent and partially ionic interactions in the ZrB bonds. The hardness value for this phase unexpectedly reaches 45.41 GPa under ambient pressure, higher than the lower limit of superhard materials.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141098915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yining Jiao, Takahide Nukariya, Umi Takatsu, T. Narita, T. Kachi, Taketomo Sato, M. Akazawa
The process‐dependent properties of Al2O3/p‐type GaN (p‐GaN) interfaces formed by atomic layer deposition at 300 °C after photoelectrochemical (PEC) etching are reported. For investigating the gap states at the Al2O3/p‐GaN interface, metal‐oxide‐semiconductor (MOS) diodes are fabricated and examined by sub‐bandgap‐light‐assisted and temperature‐dependent capacitance–voltage (C–V) measurements. PEC etching prior to Al2O3/p‐GaN interface formation is conducted with the etching depth varied in the range between 12.5 and 32.1 nm. The C–V characteristics of the MOS diodes without PEC etching indicate Fermi‐level pinning due to the near‐surface defect level in p‐GaN at 0.7 eV above the valence band edge EV and a high density of gap states around the midgap. However, all samples with PEC etching exhibit C–V characteristics, indicating a reduction in the density of the defect states at EV + 0.7 eV and midgap states. Still, PEC etching after capless annealing at 800 °C for the activation of Mg acceptors cannot reduce the density of gap states near the valence band edge. On the other hand, annealing of a sample with a SiO2 cap layer at 800 °C after PEC etching can reduce the gap state density near the valence band edge.
报告了光电化学（PEC）蚀刻后在 300 ℃ 下通过原子层沉积形成的 Al2O3/p 型氮化镓（p-GaN）界面随工艺变化的特性。为了研究 Al2O3/p-GaN 界面的间隙态，制作了金属氧化物半导体 (MOS) 二极管，并通过亚带隙光辅助和随温度变化的电容电压 (C-V) 测量进行了检验。在形成 Al2O3/p-GaN 接口之前进行了 PEC 刻蚀，刻蚀深度在 12.5 至 32.1 nm 之间变化。未进行 PEC 刻蚀的 MOS 二极管的 C-V 特性表明，由于 p-GaN 中的价带边缘 EV 上 0.7 eV 处的近表面缺陷电平以及中隙周围的高密度间隙态，导致费米级钉销。然而，所有经过 PEC 蚀刻的样品都显示出 C-V 特性，表明 EV + 0.7 eV 处的缺陷态密度和中隙态密度有所降低。不过，在 800 °C 下进行无帽退火以激活镁接受体后再进行 PEC 蚀刻，并不能降低价带边缘附近的间隙态密度。另一方面，在进行 PEC 蚀刻后，在 800 °C 下退火带有二氧化硅帽层的样品，可以降低价带边缘附近的间隙态密度。
{"title":"Reduction in Gap State Density near Valence Band Edge at Al2O3/p‐type GaN Interface by Photoelectrochemical Etching and Subsequent SiO2 Cap Annealing","authors":"Yining Jiao, Takahide Nukariya, Umi Takatsu, T. Narita, T. Kachi, Taketomo Sato, M. Akazawa","doi":"10.1002/pssb.202400025","DOIUrl":"https://doi.org/10.1002/pssb.202400025","url":null,"abstract":"The process‐dependent properties of Al2O3/p‐type GaN (p‐GaN) interfaces formed by atomic layer deposition at 300 °C after photoelectrochemical (PEC) etching are reported. For investigating the gap states at the Al2O3/p‐GaN interface, metal‐oxide‐semiconductor (MOS) diodes are fabricated and examined by sub‐bandgap‐light‐assisted and temperature‐dependent capacitance–voltage (C–V) measurements. PEC etching prior to Al2O3/p‐GaN interface formation is conducted with the etching depth varied in the range between 12.5 and 32.1 nm. The C–V characteristics of the MOS diodes without PEC etching indicate Fermi‐level pinning due to the near‐surface defect level in p‐GaN at 0.7 eV above the valence band edge EV and a high density of gap states around the midgap. However, all samples with PEC etching exhibit C–V characteristics, indicating a reduction in the density of the defect states at EV + 0.7 eV and midgap states. Still, PEC etching after capless annealing at 800 °C for the activation of Mg acceptors cannot reduce the density of gap states near the valence band edge. On the other hand, annealing of a sample with a SiO2 cap layer at 800 °C after PEC etching can reduce the gap state density near the valence band edge.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140972949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Herein, the water vapor transmission rate (WVTR) of aluminum oxide (Al2O3) films on polyethylene terephthalate (PET) substrates is investigated and is focused on the impact of the film defects on the transmission rate. The aluminum oxide films are prepared on PET substrates by magnetron sputtering, and the effects of the film thickness, sputtering power, temperature, and bias voltage on the WVTR are studied. The surface morphologies of the films are examined using atomic force microscopy (AFM), and a method for obtaining the defect ratio of the film from AFM images is proposed. Subsequently, the influences of the defect ratio on the WVTR are quantitatively evaluated based on a 3D diffusion model. The simulated WVTR values are well in agreement with the experimental ones.
{"title":"Water Vapor Permeation in Alumina Films on Polymer Substrates","authors":"Zhuoting Cai, Yingke Chen, Xingyu Chen, Jiangyong Wang, S. Lian, Congkang Xu","doi":"10.1002/pssb.202300454","DOIUrl":"https://doi.org/10.1002/pssb.202300454","url":null,"abstract":"\u0000Herein, the water vapor transmission rate (WVTR) of aluminum oxide (Al2O3) films on polyethylene terephthalate (PET) substrates is investigated and is focused on the impact of the film defects on the transmission rate. The aluminum oxide films are prepared on PET substrates by magnetron sputtering, and the effects of the film thickness, sputtering power, temperature, and bias voltage on the WVTR are studied. The surface morphologies of the films are examined using atomic force microscopy (AFM), and a method for obtaining the defect ratio of the film from AFM images is proposed. Subsequently, the influences of the defect ratio on the WVTR are quantitatively evaluated based on a 3D diffusion model. The simulated WVTR values are well in agreement with the experimental ones.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139792885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Herein, the water vapor transmission rate (WVTR) of aluminum oxide (Al2O3) films on polyethylene terephthalate (PET) substrates is investigated and is focused on the impact of the film defects on the transmission rate. The aluminum oxide films are prepared on PET substrates by magnetron sputtering, and the effects of the film thickness, sputtering power, temperature, and bias voltage on the WVTR are studied. The surface morphologies of the films are examined using atomic force microscopy (AFM), and a method for obtaining the defect ratio of the film from AFM images is proposed. Subsequently, the influences of the defect ratio on the WVTR are quantitatively evaluated based on a 3D diffusion model. The simulated WVTR values are well in agreement with the experimental ones.
{"title":"Water Vapor Permeation in Alumina Films on Polymer Substrates","authors":"Zhuoting Cai, Yingke Chen, Xingyu Chen, Jiangyong Wang, S. Lian, Congkang Xu","doi":"10.1002/pssb.202300454","DOIUrl":"https://doi.org/10.1002/pssb.202300454","url":null,"abstract":"\u0000Herein, the water vapor transmission rate (WVTR) of aluminum oxide (Al2O3) films on polyethylene terephthalate (PET) substrates is investigated and is focused on the impact of the film defects on the transmission rate. The aluminum oxide films are prepared on PET substrates by magnetron sputtering, and the effects of the film thickness, sputtering power, temperature, and bias voltage on the WVTR are studied. The surface morphologies of the films are examined using atomic force microscopy (AFM), and a method for obtaining the defect ratio of the film from AFM images is proposed. Subsequently, the influences of the defect ratio on the WVTR are quantitatively evaluated based on a 3D diffusion model. The simulated WVTR values are well in agreement with the experimental ones.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139852767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Tipaldi, Jevgenijs Gabrusenoks, George Chikvaidze
Perovskites have long been materials of interest in solid‐state physics. Their structure leads them to exhibit various characteristics which have both theoretical and practical interest. Lattice dynamics can give a lot of insight into a material's nature such as phase transitions, thus the research presented here focuses on that, by doing a comprehensive vibrational and structural investigation of monocrystalline YAlO3 (YAP). Polarized Raman and infrared (IR) reflectance spectroscopy are used alongside ab initio and classical calculations. In the course of this work, complete Raman spectra have been obtained, confirming new vibrational modes, predicted by ab initio calculations but previously not observed experimentally. IR reflectance spectra have been obtained for the first time for this material. Classical molecular dynamics has been employed to calculate the phonon dispersion and density of states.
长期以来，过氧化物一直是固态物理学中备受关注的材料。它们的结构使其表现出各种特性，这些特性既有理论意义，也有实用价值。晶格动力学能让人深入了解材料的性质，如相变，因此本文的研究重点就在于此，对单晶 YAlO3 (YAP) 进行了全面的振动和结构研究。偏振拉曼光谱和红外（IR）反射光谱与 ab initio 和经典计算同时使用。在这一研究过程中，我们获得了完整的拉曼光谱，证实了由 ab initio 计算所预测但以前未在实验中观察到的新振动模式。还首次获得了这种材料的红外反射光谱。经典分子动力学被用来计算声子色散和状态密度。
{"title":"Vibrational Spectroscopy of YAlO3","authors":"C. Tipaldi, Jevgenijs Gabrusenoks, George Chikvaidze","doi":"10.1002/pssb.202300481","DOIUrl":"https://doi.org/10.1002/pssb.202300481","url":null,"abstract":"Perovskites have long been materials of interest in solid‐state physics. Their structure leads them to exhibit various characteristics which have both theoretical and practical interest. Lattice dynamics can give a lot of insight into a material's nature such as phase transitions, thus the research presented here focuses on that, by doing a comprehensive vibrational and structural investigation of monocrystalline YAlO3 (YAP). Polarized Raman and infrared (IR) reflectance spectroscopy are used alongside ab initio and classical calculations. In the course of this work, complete Raman spectra have been obtained, confirming new vibrational modes, predicted by ab initio calculations but previously not observed experimentally. IR reflectance spectra have been obtained for the first time for this material. Classical molecular dynamics has been employed to calculate the phonon dispersion and density of states.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140478788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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