Pub Date : 2026-01-21DOI: 10.1016/j.matchemphys.2026.132128
Jiaqi Wang , Jian Gou , Ju Gao , Jingshuai Zhu , Zhongshen Tian , Yubo Wang
This study investigated the microstructure evolution and performance characteristics of additive manufacturing Inconel 625 material via a bottom cooling substrate system. Compared with natural cooling, bottom cooling increased the average cooling rate from 5.15 °C/s to 7.87 °C/s. This significant rate increment directly regulated the molten pool's solidification process. The results show that bottom cooling increased the cooling rate by approximately 50 %, accelerating solidification. This acceleration refined MC carbides into finer, uniformly distributed particles and reduced Laves phase size. Additionally, bottom cooling decreased the average grain size from 192.17 μm to 184.74 μm and significantly lowered the maximum pole density in the selected sample area. The deposited structure primarily consists of columnar dendrites growing continuously through the layers, with equiaxed dendrites forming at the top. The texture strength significantly diminished, effectively mitigating the anisotropy of the material. The toughness of the material improved to some extent, evidenced by a typical ductile fracture morphology in tensile testing. Compared with the natural cooling sample, the microstructure of the bottom cooling sample exhibited greater uniformity. Furthermore, bottom cooling enhances the corrosion resistance of components, reduces the corrosion current density about 6 % and increases the impedance, while reducing porosity.
{"title":"Microstructural refinement and enhanced mechanical properties of wire-arc additively manufactured Inconel 625 via a bottom cooling substrate system","authors":"Jiaqi Wang , Jian Gou , Ju Gao , Jingshuai Zhu , Zhongshen Tian , Yubo Wang","doi":"10.1016/j.matchemphys.2026.132128","DOIUrl":"10.1016/j.matchemphys.2026.132128","url":null,"abstract":"<div><div>This study investigated the microstructure evolution and performance characteristics of additive manufacturing Inconel 625 material via a bottom cooling substrate system. Compared with natural cooling, bottom cooling increased the average cooling rate from 5.15 °C/s to 7.87 °C/s. This significant rate increment directly regulated the molten pool's solidification process. The results show that bottom cooling increased the cooling rate by approximately 50 %, accelerating solidification. This acceleration refined MC carbides into finer, uniformly distributed particles and reduced Laves phase size. Additionally, bottom cooling decreased the average grain size from 192.17 μm to 184.74 μm and significantly lowered the maximum pole density in the selected sample area. The deposited structure primarily consists of columnar dendrites growing continuously through the layers, with equiaxed dendrites forming at the top. The texture strength significantly diminished, effectively mitigating the anisotropy of the material. The toughness of the material improved to some extent, evidenced by a typical ductile fracture morphology in tensile testing. Compared with the natural cooling sample, the microstructure of the bottom cooling sample exhibited greater uniformity. Furthermore, bottom cooling enhances the corrosion resistance of components, reduces the corrosion current density about 6 % and increases the impedance, while reducing porosity.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"353 ","pages":"Article 132128"},"PeriodicalIF":4.7,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025572","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 : 2026-01-21DOI: 10.1016/j.matchemphys.2026.132117
Hanli Hu , Congqing Yang , Jun Guo , Mingxi Pan , Yina Li , Hui Huang
Copper (Cu) powder, valued for its exceptional conductivity and low cost. However, their applications suffer from severe oxidation. Existing organic modification strategies overlook the intrinsic surface energy anisotropy of Cu, inadequately suppressing initial oxidation at high-active sites and consequently poor oxidation resistance. To address this limitation, this work proposes a priority targeted passivation of high-activity facets strategy. This approach recognizes that high-activity sites on Cu surfaces serve as primary triggers for oxidation reactions, by preferentially blocking O2 dissociation at these active sites, oxidation can be substantially suppressed. Three environmentally friendly modifiers — stearic acid (SA), oleic acid (OA), and 1-dodecanethiol (1-D) were screened for surface modification. Systematically investigated how their facet-selective adsorption regulates oxidation pathways in Cu particles. While OA preferentially adsorb onto high-activity Cu (220) facets, effectively inhibiting O2 dissociation at these critical sites and suppressing oxidation at its source. OA-modified Cu powder preserved 63.40 % metallic Cu after 180 °C/8h sintering and remained unoxidized after 180 days in air exposure, demonstrating exceptional antioxidation performance. This study establishes that prioritized passivation of highly energy facets is essential for enhancing the oxidation resistance of Cu powders.
{"title":"Targeted passivation of high-activity Cu (220) facet for enhanced oxidation resistance in Cu powders","authors":"Hanli Hu , Congqing Yang , Jun Guo , Mingxi Pan , Yina Li , Hui Huang","doi":"10.1016/j.matchemphys.2026.132117","DOIUrl":"10.1016/j.matchemphys.2026.132117","url":null,"abstract":"<div><div>Copper (Cu) powder, valued for its exceptional conductivity and low cost. However, their applications suffer from severe oxidation. Existing organic modification strategies overlook the intrinsic surface energy anisotropy of Cu, inadequately suppressing initial oxidation at high-active sites and consequently poor oxidation resistance. To address this limitation, this work proposes a priority targeted passivation of high-activity facets strategy. This approach recognizes that high-activity sites on Cu surfaces serve as primary triggers for oxidation reactions, by preferentially blocking O<sub>2</sub> dissociation at these active sites, oxidation can be substantially suppressed. Three environmentally friendly modifiers — stearic acid (SA), oleic acid (OA), and 1-dodecanethiol (1-D) were screened for surface modification. Systematically investigated how their facet-selective adsorption regulates oxidation pathways in Cu particles. While OA preferentially adsorb onto high-activity Cu (220) facets, effectively inhibiting O<sub>2</sub> dissociation at these critical sites and suppressing oxidation at its source. OA-modified Cu powder preserved 63.40 % metallic Cu after 180 °C/8h sintering and remained unoxidized after 180 days in air exposure, demonstrating exceptional antioxidation performance. This study establishes that prioritized passivation of highly energy facets is essential for enhancing the oxidation resistance of Cu powders.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"353 ","pages":"Article 132117"},"PeriodicalIF":4.7,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080375","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}
The bismuth–cerium bimetallic oxide (Bi2O3/CeO2) nanocrystals were synthesized using a hydrothermal method and thoroughly analyzed for their dielectric, electrical, and electrochemical properties over a wide range of temperatures and frequencies. The nanocrystals exhibited significant dielectric relaxation and field-driven polarization characteristics, with the improved capacitive response at elevated temperatures being linked to thermally activated space-charge polarization within the Bi–O framework. A maximum dielectric constant (ε′) of 22.14 was recorded at 340 K, and the steady decline in dielectric loss with increasing temperature suggested enhanced dielectric stability and lower energy dissipation during thermal stress. The optimized Bi2O3/CeO2 (1:1.25) composition demonstrated remarkable humidity sensitivity, low impedance, and excellent reversibility while exhibiting low hysteresis (∼ 1.2 % RH), affirming its multifunctional capabilities. The electrochemical analysis demonstrated a specific capacitance of 513 F/g at a scan rate of 5 mV/s (CV) and 410 F/g at a current density of 3 A/g (GCD), indicating exceptional charge storage capacity and stability under varying rates. The findings emphasize that the combined effect of Bi3+ and Ce4+ ions facilitates effective charge transfer, defect-mediated conduction, and consistent polarization dynamics. The Bi2O3/CeO2 nanostructure presents itself as a compelling option for high-temperature dielectric applications, humidity sensors, and advanced electrochemical energy storage systems. Future exploration of flexible or integrated energy-sensor platforms may significantly enhance their technological applicability in multifunctional smart devices.
{"title":"Hierarchical Bi2O3–CeO2 nanocomposites for multi-functional applications: Dielectric-Driven humidity sensing and electrochemical energy storage","authors":"Amna Bashir , Maryam Aleem , Hafiz Talha Hasnain Rana , Effat Yasin , Zahid Imran , Naveed Akhtar Shad , Kh Abd El-Aziz , Ifra Arshad , Hafiz T. Ali , Yasir Javed","doi":"10.1016/j.matchemphys.2026.132123","DOIUrl":"10.1016/j.matchemphys.2026.132123","url":null,"abstract":"<div><div>The bismuth–cerium bimetallic oxide (Bi<sub>2</sub>O<sub>3</sub>/CeO<sub>2</sub>) nanocrystals were synthesized using a hydrothermal method and thoroughly analyzed for their dielectric, electrical, and electrochemical properties over a wide range of temperatures and frequencies. The nanocrystals exhibited significant dielectric relaxation and field-driven polarization characteristics, with the improved capacitive response at elevated temperatures being linked to thermally activated space-charge polarization within the Bi–O framework. A maximum dielectric constant (<em>ε</em>′) of 22.14 was recorded at 340 K, and the steady decline in dielectric loss with increasing temperature suggested enhanced dielectric stability and lower energy dissipation during thermal stress. The optimized Bi<sub>2</sub>O<sub>3</sub>/CeO<sub>2</sub> (1:1.25) composition demonstrated remarkable humidity sensitivity, low impedance, and excellent reversibility while exhibiting low hysteresis (∼ 1.2 % RH), affirming its multifunctional capabilities. The electrochemical analysis demonstrated a specific capacitance of 513 F/g at a scan rate of 5 mV/s (CV) and 410 F/g at a current density of 3 A/g (GCD), indicating exceptional charge storage capacity and stability under varying rates. The findings emphasize that the combined effect of Bi<sup>3+</sup> and Ce<sup>4+</sup> ions facilitates effective charge transfer, defect-mediated conduction, and consistent polarization dynamics. The Bi<sub>2</sub>O<sub>3</sub>/CeO<sub>2</sub> nanostructure presents itself as a compelling option for high-temperature dielectric applications, humidity sensors, and advanced electrochemical energy storage systems. Future exploration of flexible or integrated energy-sensor platforms may significantly enhance their technological applicability in multifunctional smart devices.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"353 ","pages":"Article 132123"},"PeriodicalIF":4.7,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025554","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}
This study highlights the novel use of marine-derived biomass (specifically sepia ink) as a functional carbon precursor for the counter electrode (CE) of dye-sensitized solar cells (DSSCs). Unlike other carbon sources, sepia ink naturally produces primary particles that are spherical and rich in mineral elements. Upon KOH activation, the resulting activated biocarbon (aSBC) exhibits a dramatic increase in specific surface area, reaching 1953.3 m2 g−1. However, we found that the predominance of micropores and the presence of crystalline KCl domains, derived from the inherent elements in the precursor, create significant barriers to ion transport, hindering ion diffusion. To overcome these limitations, a composite CE was prepared by mixing activated biocarbon (SBC) and aSBC in a 1:1 ratio. This combination balances the high density of accessible catalytic sites of aSBC with the superior electron and ion pathways provided by the SBC network. The resulting DSSCs achieved a power conversion efficiency of 2.42 %, a fivefold improvement compared to single-component electrodes and comparable to noble metal Pt/FTO counter electrodes. These findings demonstrate that sepia ink-derived biocarbon is a promising and sustainable material, provided its unique pore architecture and mineral content are co-engineered to balance catalytic activity with mass transport.
{"title":"Synthesized biocarbon-based sepia ink and its application as a counter electrode for dye-sensitized solar cell","authors":"Sahrul Saehana , Darsikin Darsikin , Nefta Cahyatri Kharimah , Euis Siti Nurazizah , Quang-Duy Dao , Yuliar Firdaus , Annisa Aprilia","doi":"10.1016/j.matchemphys.2026.132125","DOIUrl":"10.1016/j.matchemphys.2026.132125","url":null,"abstract":"<div><div>This study highlights the novel use of marine-derived biomass (specifically sepia ink) as a functional carbon precursor for the counter electrode (CE) of dye-sensitized solar cells (DSSCs). Unlike other carbon sources, sepia ink naturally produces primary particles that are spherical and rich in mineral elements. Upon KOH activation, the resulting activated biocarbon (aSBC) exhibits a dramatic increase in specific surface area, reaching 1953.3 m<sup>2</sup> g<sup>−1</sup>. However, we found that the predominance of micropores and the presence of crystalline KCl domains, derived from the inherent elements in the precursor, create significant barriers to ion transport, hindering ion diffusion. To overcome these limitations, a composite CE was prepared by mixing activated biocarbon (SBC) and aSBC in a 1:1 ratio. This combination balances the high density of accessible catalytic sites of aSBC with the superior electron and ion pathways provided by the SBC network. The resulting DSSCs achieved a power conversion efficiency of 2.42 %, a fivefold improvement compared to single-component electrodes and comparable to noble metal Pt/FTO counter electrodes. These findings demonstrate that sepia ink-derived biocarbon is a promising and sustainable material, provided its unique pore architecture and mineral content are co-engineered to balance catalytic activity with mass transport.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"353 ","pages":"Article 132125"},"PeriodicalIF":4.7,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025696","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 : 2026-01-20DOI: 10.1016/j.matchemphys.2026.132100
Rihab Masmoudi , Carl P Tripp , Luke Doucette , Mauricio Pereira da Cunha
A coating consisting of layer-by-layer deposition of cationic and anionic kaolin followed by a topcoat of a sol-gel CeO2 or SiO2 is shown to provide a protective barrier against oxidation for 440 steel under thermal cyclic conditions from room temperature to 1000 °C. The kaolin layer provides a torturous path for oxygen penetration while the sol-gel based coatings CeO2 and SiO2 are conformal and fill the gaps between kaolin platelets while also improving adhesion of the kaolin coating to steel. After one thermal cycle to 1000 °C, CeO2 and SiO2 topcoats over kaolin resulted in lowering the amount of oxidation by 66 % and 98 %, respectively. On the other hand, a second thermal cycle to 1000 °C showed a 55 % lower oxidation in the CeO2/kaolin coating compared to bare 440 steel, whereas SiO2/kaolin was delaminated after the second thermal cycle. This was due to mismatch in coefficient of thermal expansion between SiO2 (0.55x10−6 K-1) and 440 steel (10.6x10−6 K-1). In contrast, the similar coefficient of thermal expansion between CeO2 (11.8x10−6 K-1) and steel (10.2x10−6 K-1) allowed it to sustain thermal cycling. After a 2nd thermal cycle at 1000 °C, XRD analysis of the kaolin/CeO2 coated sample showed that passivating Cr2O3 and Mn1.5Cr1.5O4 oxides were predominant, whereas in bare 440 steel and kaolin/SiO2 only Fe2O3 was detected.
{"title":"Investigation of the oxidation of 440 steel coated with Kaolin/CeO2 and Kaolin/SiO2 operating at high temperature cycling conditions","authors":"Rihab Masmoudi , Carl P Tripp , Luke Doucette , Mauricio Pereira da Cunha","doi":"10.1016/j.matchemphys.2026.132100","DOIUrl":"10.1016/j.matchemphys.2026.132100","url":null,"abstract":"<div><div>A coating consisting of layer-by-layer deposition of cationic and anionic kaolin followed by a topcoat of a sol-gel CeO<sub>2</sub> or SiO<sub>2</sub> is shown to provide a protective barrier against oxidation for 440 steel under thermal cyclic conditions from room temperature to 1000 °C. The kaolin layer provides a torturous path for oxygen penetration while the sol-gel based coatings CeO<sub>2</sub> and SiO<sub>2</sub> are conformal and fill the gaps between kaolin platelets while also improving adhesion of the kaolin coating to steel. After one thermal cycle to 1000 °C, CeO<sub>2</sub> and SiO<sub>2</sub> topcoats over kaolin resulted in lowering the amount of oxidation by 66 % and 98 %, respectively. On the other hand, a second thermal cycle to 1000 °C showed a 55 % lower oxidation in the CeO<sub>2</sub>/kaolin coating compared to bare 440 steel, whereas SiO<sub>2</sub>/kaolin was delaminated after the second thermal cycle. This was due to mismatch in coefficient of thermal expansion between SiO<sub>2</sub> (0.55x10<sup>−6</sup> K<sup>-1</sup>) and 440 steel (10.6x10<sup>−6</sup> K<sup>-1</sup>). In contrast, the similar coefficient of thermal expansion between CeO<sub>2</sub> (11.8x10<sup>−6</sup> K<sup>-1</sup>) and steel (10.2x10<sup>−6</sup> K<sup>-1</sup>) allowed it to sustain thermal cycling. After a 2nd thermal cycle at 1000 °C, XRD analysis of the kaolin/CeO<sub>2</sub> coated sample showed that passivating Cr<sub>2</sub>O<sub>3</sub> and Mn<sub>1.5</sub>Cr<sub>1.5</sub>O<sub>4</sub> oxides were predominant, whereas in bare 440 steel and kaolin/SiO<sub>2</sub> only Fe<sub>2</sub>O<sub>3</sub> was detected.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"353 ","pages":"Article 132100"},"PeriodicalIF":4.7,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026021","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 report a comprehensive first-principles investigation of cubic vacancy-ordered halide double perovskites A2BBr6 (A = Rb, Cs; BS, Se). Structural optimization confirms cubic Fm-3m symmetry with lattice parameters of 10.96–11.35 Å and formation energies around −2 eV, indicating thermodynamically favorable formation. The compounds exhibit indirect semiconducting behavior with band gaps of 2.21 eV (Cs2SBr6), 2.25 eV (Rb2SBr6), 2.70 eV (Cs2SeBr6), and 2.75 eV (Rb2SeBr6). Elastic constants satisfy Born's criteria, with bulk moduli ranging from 14.94 GPa (Cs2SeBr6) to 20.57 GPa (Rb2SBr6) and Young's moduli up to 32.4 GPa, revealing brittle behavior and significant elastic anisotropy. The Debye temperatures vary between 162 K (Cs2SeBr6) and 203 K (Rb2SBr6), correlating with lattice stiffness. Optical calculations show strong visible and UV absorption, with coefficients up to 110 × 104 cm−1 and static refractive indices n(0) of 1.91–2.11, highlighting potential for photonic and UV applications. Thermoelectric properties demonstrate high Seebeck coefficients (1.72–1.90 × 10−4 V/K) and low thermal conductivity, yielding figure-of-merit ZT values of 0.12–0.23 at 300 K, increasing to 0.39–0.56 at 900 K. These results establish A2BBr6 compounds as promising candidates for multifunctional optoelectronic and high-temperature thermoelectric applications.
我们报道了一个全面的第一性原理研究立方空位有序卤化物双钙钛矿A2BBr6 （a = Rb, Cs； BS, Se）。结构优化证实了立方Fm-3m对称，晶格参数为10.96-11.35 Å，地层能量约为- 2 eV，表明热力学有利的形成。化合物具有间接半导体行为，带隙分别为2.21 eV （Cs2SBr6）、2.25 eV （Rb2SBr6）、2.70 eV （Cs2SeBr6）和2.75 eV （Rb2SeBr6）。弹性常数满足玻恩准则，体积模量为14.94 GPa (Cs2SeBr6) ~ 20.57 GPa (Rb2SBr6)，杨氏模量为32.4 GPa，表现出脆性行为和显著的弹性各向异性。德拜温度在162 K （Cs2SeBr6）和203 K （Rb2SBr6）之间变化，与晶格刚度相关。光学计算显示出强的可见光和紫外吸收，系数高达110 × 104 cm−1，静态折射率n(0)为1.91-2.11，突出了光子和紫外应用的潜力。热电性能表现出高塞贝克系数（1.72-1.90 × 10−4 V/K）和低导热系数，在300 K时产生0.12-0.23的优点系数ZT值，在900 K时增加到0.39-0.56。这些结果表明A2BBr6化合物是多功能光电和高温热电应用的有希望的候选者。
{"title":"Multifunctional properties of cubic vacancy-ordered double halide perovskites A2BBr6 (A = Rb, Cs; BS, se) for optoelectronic and thermoelectric applications","authors":"Djelti Radouan, Benahmedi Lakhdar, Besbes Anissa, Aissani Ali, Bendehiba Sid Ahmed","doi":"10.1016/j.matchemphys.2026.132114","DOIUrl":"10.1016/j.matchemphys.2026.132114","url":null,"abstract":"<div><div>We report a comprehensive first-principles investigation of cubic vacancy-ordered halide double perovskites A<sub>2</sub>BBr<sub>6</sub> (A = Rb, Cs; B<img>S, Se). Structural optimization confirms cubic Fm-3m symmetry with lattice parameters of 10.96–11.35 Å and formation energies around −2 eV, indicating thermodynamically favorable formation. The compounds exhibit indirect semiconducting behavior with band gaps of 2.21 eV (Cs<sub>2</sub>SBr<sub>6</sub>), 2.25 eV (Rb<sub>2</sub>SBr<sub>6</sub>), 2.70 eV (Cs<sub>2</sub>SeBr<sub>6</sub>), and 2.75 eV (Rb<sub>2</sub>SeBr<sub>6</sub>). Elastic constants satisfy Born's criteria, with bulk moduli ranging from 14.94 GPa (Cs<sub>2</sub>SeBr<sub>6</sub>) to 20.57 GPa (Rb<sub>2</sub>SBr<sub>6</sub>) and Young's moduli up to 32.4 GPa, revealing brittle behavior and significant elastic anisotropy. The Debye temperatures vary between 162 K (Cs<sub>2</sub>SeBr<sub>6</sub>) and 203 K (Rb<sub>2</sub>SBr<sub>6</sub>), correlating with lattice stiffness. Optical calculations show strong visible and UV absorption, with coefficients up to 110 × 10<sup>4</sup> cm<sup>−1</sup> and static refractive indices n(0) of 1.91–2.11, highlighting potential for photonic and UV applications. Thermoelectric properties demonstrate high Seebeck coefficients (1.72–1.90 × 10<sup>−4</sup> V/K) and low thermal conductivity, yielding figure-of-merit ZT values of 0.12–0.23 at 300 K, increasing to 0.39–0.56 at 900 K. These results establish A<sub>2</sub>BBr<sub>6</sub> compounds as promising candidates for multifunctional optoelectronic and high-temperature thermoelectric applications.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"353 ","pages":"Article 132114"},"PeriodicalIF":4.7,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080373","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 : 2026-01-20DOI: 10.1016/j.matchemphys.2026.132115
Łukasz Szeleszczuk , Katarzyna Mądra-Gackowska , Marcin Gackowski
This study presents a first-principles investigation of the structural, electronic, mechanical, thermal, and thermoelectric properties of X2YN2 (X = Zr, Hf; YS, Se) Zintl phase compounds. Structural and mechanical characteristics were evaluated using the GGA-PBE functional, while the electronic and transport properties were calculated with the hybrid HSE06 functional. Each compound crystallizes with trigonal crystal structure (space group P 1). Negative formation energies, positive phonon frequencies, and compliance with the Born stability criteria confirm the structural, thermodynamic, and mechanical stability of these compounds. They exhibit indirect semiconducting behavior with HSE06 band gap of 1.313 eV (Zr2SN2), 1.078 eV (Zr2SeN2) and 1.610 eV (Hf2SN2) and are dominated by p-d orbital interactions. Charge density and projected density of states (PDOS) analyses reveal a gradual transition from ionic to covalent bonding, with Hf2SeN2 showing the strongest covalent character. The alloys of Zr2SN2 and Zr2SeN2 are brittle and Hf2SeN2 is ductile and they are all anisotropic elastic. Thermal measurements indicate that Zr2SN2 exhibits the largest Debye temperature and thermal conductivity, and Se based compounds exhibit greater anharmonicity. Thermoelectric calculations show that Zr2SN2 achieves a ZT of 0.84 at 300 K and 2.09 at 1000 K, Zr2SeN2 increases from 0.94 at 300 K to 2.21 at 1000 K, and Hf2SeN2 rises from 0.93 at 300 K to 2.44 at 1000 K. These results highlight the promising thermoelectric performance of these materials not only at elevated temperatures but also under room-temperature conditions, suggesting their potential for both mid and high temperature thermoelectric applications.
本研究对X2YN2 (X = Zr, Hf； YS, Se) Zintl相化合物的结构、电子、机械、热学和热电性质进行了第一性原理研究。使用GGA-PBE函数评估结构和力学特性，而使用混合HSE06函数计算电子和输运特性。每种化合物结晶时具有三角形晶体结构（空间群p3形式的m1形式）。负的形成能，正的声子频率，符合玻恩稳定性准则，证实了这些化合物的结构、热力学和机械稳定性。它们表现出间接半导体行为，HSE06带隙分别为1.313 eV （Zr2SN2）、1.078 eV （Zr2SeN2）和1.610 eV (Hf2SN2)，并以p-d轨道相互作用为主。电荷密度和投影态密度（PDOS）分析揭示了从离子键到共价键的逐渐转变，其中Hf2SeN2表现出最强的共价键特征。Zr2SN2和Zr2SeN2合金为脆性合金，Hf2SeN2合金为延展性合金，均为各向异性弹性合金。热测量结果表明，Zr2SN2具有最大的德拜温度和热导率，Se基化合物具有较大的非调和性。热电计算表明，Zr2SN2在300 K时ZT为0.84，在1000 K时ZT为2.09，Zr2SeN2从300 K时的0.94上升到1000 K时的2.21，Hf2SeN2从300 K时的0.93上升到1000 K时的2.44。这些结果突出了这些材料不仅在高温下而且在室温条件下具有良好的热电性能，表明它们具有中高温热电应用的潜力。
{"title":"High-efficiency thermoelectric performance of X2YN2 (X = Zr, Hf; YS, Se) Zintl phases: A first-principles study","authors":"Łukasz Szeleszczuk , Katarzyna Mądra-Gackowska , Marcin Gackowski","doi":"10.1016/j.matchemphys.2026.132115","DOIUrl":"10.1016/j.matchemphys.2026.132115","url":null,"abstract":"<div><div>This study presents a first-principles investigation of the structural, electronic, mechanical, thermal, and thermoelectric properties of <em>X</em><sub>2</sub><em>Y</em>N<sub>2</sub> (<em>X</em> = Zr, Hf; <em>Y</em><img>S, Se) Zintl phase compounds. Structural and mechanical characteristics were evaluated using the GGA-PBE functional, while the electronic and transport properties were calculated with the hybrid HSE06 functional. Each compound crystallizes with trigonal crystal structure (space group P <span><math><mrow><mover><mn>3</mn><mo>‾</mo></mover><mi>m</mi></mrow></math></span> 1). Negative formation energies, positive phonon frequencies, and compliance with the Born stability criteria confirm the structural, thermodynamic, and mechanical stability of these compounds. They exhibit indirect semiconducting behavior with HSE06 band gap of 1.313 eV (Zr<sub>2</sub>SN<sub>2</sub>), 1.078 eV (Zr<sub>2</sub>SeN<sub>2</sub>) and 1.610 eV (Hf<sub>2</sub>SN<sub>2</sub>) and are dominated by <em>p</em>-<em>d</em> orbital interactions. Charge density and projected density of states (PDOS) analyses reveal a gradual transition from ionic to covalent bonding, with Hf<sub>2</sub>SeN<sub>2</sub> showing the strongest covalent character. The alloys of Zr<sub>2</sub>SN<sub>2</sub> and Zr<sub>2</sub>SeN<sub>2</sub> are brittle and Hf<sub>2</sub>SeN<sub>2</sub> is ductile and they are all anisotropic elastic. Thermal measurements indicate that Zr<sub>2</sub>SN<sub>2</sub> exhibits the largest Debye temperature and thermal conductivity, and Se based compounds exhibit greater anharmonicity. Thermoelectric calculations show that Zr<sub>2</sub>SN<sub>2</sub> achieves a ZT of 0.84 at 300 K and 2.09 at 1000 K, Zr<sub>2</sub>SeN<sub>2</sub> increases from 0.94 at 300 K to 2.21 at 1000 K, and Hf<sub>2</sub>SeN<sub>2</sub> rises from 0.93 at 300 K to 2.44 at 1000 K. These results highlight the promising thermoelectric performance of these materials not only at elevated temperatures but also under room-temperature conditions, suggesting their potential for both mid and high temperature thermoelectric applications.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"353 ","pages":"Article 132115"},"PeriodicalIF":4.7,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025546","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 : 2026-01-20DOI: 10.1016/j.matchemphys.2026.132111
Yeonkyu Lee , Juan C. Zapata , Chanyoung Lee , Jinyoung Yun , Martin Sirena , Jeehoon Kim , Nestor Haberkorn
We demonstrate the integration of ferroelectric and superconducting functionalities in NbN/Al0.7Sc0.3N (AlScN) bilayers grown by reactive sputtering on c-cut sapphire. The NbN thickness was fixed at 10 nm, while the AlScN layer was varied from 4.5 to 20 nm. All samples display atomically flat surfaces and sharp interfaces, suitable for vertical integration in multilayer device architectures. Local ferroelectric-like functionality is evidenced by PFM (near-180° phase reversals), with local coercive voltages in the range 0.4–1.1 V. Because PFM can include electrostatic contributions, these values are used only as local thresholds rather than those of macroscopic planar capacitors. Despite robust local switching, domain writing experiments reveal a progressive loss of remanent contrast in thinner films, indicating partial degradation of the macroscopic response. Low-temperature transport under controlled polarization states (±10 V) shows no measurable change in resistance or transition temperature, which remains above 15 K—suggesting clean interfaces and minimal electrostatic or proximity-induced suppression. These results imply that the coupling between ferroelectric and superconducting layers is limited at these thicknesses, due to interfacial disorder or inhomogeneous polarization. This work establishes a chemically compatible and scalable nitride platform, opening a path toward more robust, electrically tunable ferroelectric/superconducting devices in cryogenic electronics.
{"title":"Structural and functional integration of superconductivity and ferroelectricity in ultrathin NbN/AlScN bilayers","authors":"Yeonkyu Lee , Juan C. Zapata , Chanyoung Lee , Jinyoung Yun , Martin Sirena , Jeehoon Kim , Nestor Haberkorn","doi":"10.1016/j.matchemphys.2026.132111","DOIUrl":"10.1016/j.matchemphys.2026.132111","url":null,"abstract":"<div><div>We demonstrate the integration of ferroelectric and superconducting functionalities in NbN/Al<sub>0.7</sub>Sc<sub>0.3</sub>N (AlScN) bilayers grown by reactive sputtering on <em>c</em>-cut sapphire. The NbN thickness was fixed at 10 nm, while the AlScN layer was varied from 4.5 to 20 nm. All samples display atomically flat surfaces and sharp interfaces, suitable for vertical integration in multilayer device architectures. Local ferroelectric-like functionality is evidenced by PFM (near-180° phase reversals), with local coercive voltages in the range 0.4–1.1 V. Because PFM can include electrostatic contributions, these values are used only as local thresholds rather than those of macroscopic planar capacitors. Despite robust local switching, domain writing experiments reveal a progressive loss of remanent contrast in thinner films, indicating partial degradation of the macroscopic response. Low-temperature transport under controlled polarization states (±10 V) shows no measurable change in resistance or transition temperature, which remains above 15 K—suggesting clean interfaces and minimal electrostatic or proximity-induced suppression. These results imply that the coupling between ferroelectric and superconducting layers is limited at these thicknesses, due to interfacial disorder or inhomogeneous polarization. This work establishes a chemically compatible and scalable nitride platform, opening a path toward more robust, electrically tunable ferroelectric/superconducting devices in cryogenic electronics.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"353 ","pages":"Article 132111"},"PeriodicalIF":4.7,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025569","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 : 2026-01-20DOI: 10.1016/j.matchemphys.2026.132051
Yandong Che, Jiacheng Ding, Xu Wang, Peng Song, Yanqiu Yang
This study presents a systematic investigation of distance-dependent electromagnetic enhancement in surface-enhanced Raman scattering (SERS) substrates based on silver nanostructures. Finite-difference time-domain (FDTD) simulations are employed to evaluate the electromagnetic enhancement factor (MEM) of identical silver nanostructures with varying inter-particle spacings. The results demonstrate that the spacing-dependent electromagnetic enhancement is highly sensitive to nanogap modulation and strongly dependent on structural geometry within the physically meaningful regime accessible to classical electrodynamics.
Specifically, for silver nanorod arrays, the MEM increases continuously as the inter-particle spacing is reduced from 1.0 nm to 0.3 nm, reaching a maximum value of 7.7 × 105 at 0.6 nm within the investigated range. In contrast, for silver nanosphere dimers, the MEM exhibits a non-monotonic dependence on spacing as the gap decreases from 1.2 nm to 0.3 nm, increasing markedly and reaching a maximum of 7.2 × 106 at approximately 1.0 nm, followed by a reduction at smaller spacings. Similarly, for nested silver nanocylinder shell structures, the MEM reaches an optimal value of 8.2 × 103 at a spacing of approximately 0.6 nm as the inter-particle distance is reduced from 1.0 nm to 0.3 nm. These results indicate that different silver nanostructures possess distinct spacing-dependent electromagnetic enhancement behaviors and characteristic optimal nanogap ranges.
Furthermore, 4-mercaptobenzoic acid (4-MBA) molecules are employed as probe molecules, and density functional theory (DFT) calculations are performed to qualitatively analyze molecule-metal interactions and chemical enhancement effects. By integrating electromagnetic simulations with electronic structure analysis, this work provides practical guidance for rational nanogap engineering and the design of high-performance SERS substrates.
{"title":"Distance factor regulation on the Raman scattering enhancement performance of three-dimensional full-field nano silver structures","authors":"Yandong Che, Jiacheng Ding, Xu Wang, Peng Song, Yanqiu Yang","doi":"10.1016/j.matchemphys.2026.132051","DOIUrl":"10.1016/j.matchemphys.2026.132051","url":null,"abstract":"<div><div>This study presents a systematic investigation of distance-dependent electromagnetic enhancement in surface-enhanced Raman scattering (SERS) substrates based on silver nanostructures. Finite-difference time-domain (FDTD) simulations are employed to evaluate the electromagnetic enhancement factor (MEM) of identical silver nanostructures with varying inter-particle spacings. The results demonstrate that the spacing-dependent electromagnetic enhancement is highly sensitive to nanogap modulation and strongly dependent on structural geometry within the physically meaningful regime accessible to classical electrodynamics.</div><div>Specifically, for silver nanorod arrays, the MEM increases continuously as the inter-particle spacing is reduced from 1.0 nm to 0.3 nm, reaching a maximum value of 7.7 × 10<sup>5</sup> at 0.6 nm within the investigated range. In contrast, for silver nanosphere dimers, the MEM exhibits a non-monotonic dependence on spacing as the gap decreases from 1.2 nm to 0.3 nm, increasing markedly and reaching a maximum of 7.2 × 10<sup>6</sup> at approximately 1.0 nm, followed by a reduction at smaller spacings. Similarly, for nested silver nanocylinder shell structures, the MEM reaches an optimal value of 8.2 × 10<sup>3</sup> at a spacing of approximately 0.6 nm as the inter-particle distance is reduced from 1.0 nm to 0.3 nm. These results indicate that different silver nanostructures possess distinct spacing-dependent electromagnetic enhancement behaviors and characteristic optimal nanogap ranges.</div><div>Furthermore, 4-mercaptobenzoic acid (4-MBA) molecules are employed as probe molecules, and density functional theory (DFT) calculations are performed to qualitatively analyze molecule-metal interactions and chemical enhancement effects. By integrating electromagnetic simulations with electronic structure analysis, this work provides practical guidance for rational nanogap engineering and the design of high-performance SERS substrates.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"353 ","pages":"Article 132051"},"PeriodicalIF":4.7,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025555","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 : 2026-01-20DOI: 10.1016/j.matchemphys.2026.132126
Yousef A. Bin Jardan , A.Q. Khaleel , Prakash Kanjariya , Suhas Ballal , Abhayveer Singh , T. Krithiga , Laxmidhar Maharana , M.K. Reem , H.R. Salman , Mounir M. Bekhit
This study employs density functional theory (DFT) simulations to systematically investigate the electronic sensitivity of pristine irida-graphene monolayer (PIGrML) and Al-decorated IGrML (Al@IGrML) toward temozolomide (TMZ) adsorption. While TMZ exhibits weak physisorption on PIGrML (Eads = −0.308 eV), Al decoration dramatically enhances chemisorption on Al@IGrML (Eads = −0.862 eV), accompanied by substantial charge transfer (0.242 e) and HOMO-LUMO gap reduction that boosts electrical conductance. These modifications yield a highly reactive sensor platform with excellent structural stability at ambient temperature and rapid recovery time (τ = 3.36 s at 300 K). Al@IGrML emerges as an ideal TMZ nanosensor, paving the way for advanced biomolecule detection nanomaterials.
{"title":"DFT study of Irida-graphene decorated with aluminum as a sensor for temozolomide drug","authors":"Yousef A. Bin Jardan , A.Q. Khaleel , Prakash Kanjariya , Suhas Ballal , Abhayveer Singh , T. Krithiga , Laxmidhar Maharana , M.K. Reem , H.R. Salman , Mounir M. Bekhit","doi":"10.1016/j.matchemphys.2026.132126","DOIUrl":"10.1016/j.matchemphys.2026.132126","url":null,"abstract":"<div><div>This study employs density functional theory (DFT) simulations to systematically investigate the electronic sensitivity of pristine irida-graphene monolayer (PIGrML) and Al-decorated IGrML (Al@IGrML) toward temozolomide (TMZ) adsorption. While TMZ exhibits weak physisorption on PIGrML (E<sub>ads</sub> = −0.308 eV), Al decoration dramatically enhances chemisorption on Al@IGrML (E<sub>ads</sub> = −0.862 eV), accompanied by substantial charge transfer (0.242 e) and HOMO-LUMO gap reduction that boosts electrical conductance. These modifications yield a highly reactive sensor platform with excellent structural stability at ambient temperature and rapid recovery time (τ = 3.36 s at 300 K). Al@IGrML emerges as an ideal TMZ nanosensor, paving the way for advanced biomolecule detection nanomaterials.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"353 ","pages":"Article 132126"},"PeriodicalIF":4.7,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025557","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号