Banat Gul , Safia Abdullah R Alharbi , Muhammad Salman Khan , Siti Maisarah Aziz
{"title":"Substitutional impact of alkali metals on the electronic structure, optical, mechanical, and transport properties of novel ternary materials","authors":"Banat Gul , Safia Abdullah R Alharbi , Muhammad Salman Khan , Siti Maisarah Aziz","doi":"10.1016/j.micrna.2025.208374","DOIUrl":null,"url":null,"abstract":"<div><div>This study investigates the structure, optoelectronic, mechanical, and transport features of two novel NaAcTe<sub>2</sub> and RbAcTe<sub>2</sub> chalcogenides, using first-principles calculations. Both materials crystallize in the cubic F <span><math><mrow><mover><mi>m</mi><mo>̅</mo></mover></mrow></math></span> 3 m phase, while RbAcTe<sub>2</sub> has higher thermodynamic stability because of its negative formation energy (−3.52 eV/atom) and larger lattice constants. TB-mBJ electronic band structure modelling indicates that both compounds are direct band gap semiconductors, with RbAcTe<sub>2</sub> (1.62 eV) having a larger energy gap than NaAcTe<sub>2</sub> (1.29 eV). The density of states analysis indicates that Te-p and Ac-f/d contributions are prevalent near the Fermi level, suggesting favorable electronic transitions and improved thermoelectric response. NaAcTe<sub>2</sub> has stronger dielectric function peaks, greater absorption in the 4–12 eV range, and larger reflectivity, indicating better light-matter interaction and plasmonic performance. Mechanical investigation shows that both materials are ductile and mechanically stable. RbAcTe<sub>2</sub> has greater elastic constants although NaAcTe<sub>2</sub> is more ductile. NaAcTe<sub>2</sub> has greater electrical conductivity and ZT = 0.32 at 700 K) compared to RbAcTe<sub>2</sub>, which has a higher Seebeck coefficient. These results demonstrate that NaAcTe<sub>2</sub> is appropriate for optical and thermoelectric devices that require a balance of mechanical flexibility and conductivity, whereas RbAcTe<sub>2</sub> is well-suited for high-stability, rigid device configurations.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"208 ","pages":"Article 208374"},"PeriodicalIF":3.0000,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Micro and Nanostructures","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2773012325003036","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, CONDENSED MATTER","Score":null,"Total":0}
引用次数: 0
Abstract
This study investigates the structure, optoelectronic, mechanical, and transport features of two novel NaAcTe2 and RbAcTe2 chalcogenides, using first-principles calculations. Both materials crystallize in the cubic F 3 m phase, while RbAcTe2 has higher thermodynamic stability because of its negative formation energy (−3.52 eV/atom) and larger lattice constants. TB-mBJ electronic band structure modelling indicates that both compounds are direct band gap semiconductors, with RbAcTe2 (1.62 eV) having a larger energy gap than NaAcTe2 (1.29 eV). The density of states analysis indicates that Te-p and Ac-f/d contributions are prevalent near the Fermi level, suggesting favorable electronic transitions and improved thermoelectric response. NaAcTe2 has stronger dielectric function peaks, greater absorption in the 4–12 eV range, and larger reflectivity, indicating better light-matter interaction and plasmonic performance. Mechanical investigation shows that both materials are ductile and mechanically stable. RbAcTe2 has greater elastic constants although NaAcTe2 is more ductile. NaAcTe2 has greater electrical conductivity and ZT = 0.32 at 700 K) compared to RbAcTe2, which has a higher Seebeck coefficient. These results demonstrate that NaAcTe2 is appropriate for optical and thermoelectric devices that require a balance of mechanical flexibility and conductivity, whereas RbAcTe2 is well-suited for high-stability, rigid device configurations.