Awan Mazhar Haleem, Munsif Sehrish, Habib Huma
Department of Physics, Abbottabad University of Science and Technology Abbottabad KPK Pakistan
CAS Key Laboratory of Science and Technology on Applied Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Science Dalian 116023 China
RSC Adv. 2025 Aug 18;15(36):29129-29141. doi: 10.1039/d5ra04332h.
Perovskite chalcogenides have attracted significant interest due to their potential applications in optoelectronics, catalysis, and renewable energy systems. This paper examines the structural, electronic, elastic, and phononic properties of KMgX (X = O, S, Se) using density functional theory (DFT) in the context of the full-potential linearized augmented plane wave plus local orbital (FP-LAPW + lo) approach. Their stability in the cubic phase (3̄ symmetry) is confirmed by the computed lattice parameters for KMgO (4.1325 Å), KMgS (5.0008 Å), and KMgSe (5.2070 Å). KMgO exhibits semiconducting behavior with a direct bandgap of 7.323 eV in the spin-up state, according to electronic band structure studies, whereas KMgS and KMgSe show metallic properties. Elastic constants (C, C, and C) meet the requirements for mechanical stability, which is evaluated using the Born criterion. Upon further examination of mechanical characteristics such as Bulk modulus, Shear modulus, Young's modulus, and Poisson's ratio. Materials such as KMgO and KMgS exhibit ductile behavior, whereas KMgSe exhibits brittleness. Phonon dispersion curves and molecular dynamics simulations confirm the dynamical and thermal stability of these compounds. The results show that KMgX perovskites have potential uses in optoelectronic devices and spintronics.
钙钛矿硫族化合物因其在光电子学、催化和可再生能源系统中的潜在应用而引起了广泛关注。本文采用全势线性缀加平面波加局域轨道（FP-LAPW + lo）方法，在密度泛函理论（DFT）的框架下研究了KMgX（X = O、S、Se）的结构、电子、弹性和声子性质。通过计算得到的KMgO（4.1325 Å）、KMgS（5.0008 Å）和KMgSe（5.2070 Å）的晶格参数，证实了它们在立方相（3̄对称性）中的稳定性。根据电子能带结构研究，KMgO在自旋向上状态下表现出半导体行为，直接带隙为7.323 eV，而KMgS和KMgSe表现出金属性质。弹性常数（C、C和C）满足机械稳定性的要求，这是根据玻恩准则进行评估的。进一步研究诸如体模量、剪切模量、杨氏模量和泊松比等力学特性时发现，KMgO和KMgS等材料表现出韧性，而KMgSe表现出脆性。声子色散曲线和分子动力学模拟证实了这些化合物的动力学和热稳定性。结果表明，KMgX钙钛矿在光电器件和自旋电子学中具有潜在应用。
