Akademik Veri Yönetim Sistemi
Journal of the American Ceramic Society, cilt.109, sa.5, 2026 (SCI-Expanded, Scopus)
In the quest for next-generation technology, spintronics and optoelectronics have emerged as pivotal fields for developing energy-efficient and high-speed devices. Vacancy-ordered double perovskites are promising candidates for these applications due to the tunability of their band gaps, their robust spin polarization at the Fermi level, and their environmental stability. This research presents a comprehensive ab initio investigation of the quaternary Cs2VCl6, Cs2Vl6, and Cs2VBr6 compounds, leveraging an all-electron Density Functional Theory (DFT) approach, implemented through the high-precision Full-Potential Linearized Augmented Plane-Wave (FP-LAPW) formalism, as embodied within the WIEN2k computational suite. To ensure high accuracy, the TB-mBJ potential was utilized for electronic and optical excitations. Structural relaxation verified that all studied configurations reside in a global energy minimum, ensuring both the mechanical robustness and dynamical stability of the cubic phase. Electronic and magnetic analyses revealed that these vacancy-ordered double perovskites exhibit a robust half-metallic ferromagnetic ground state with a fully quantized total magnetic moment of 1.00 (Formula presented.). Specifically, they display minority-channel spin-flip gaps of 2.94, 2.36, and 1.45 eV for Cs2Vcl6, Cs2VBr6, and Cs2Vl6, respectively. Furthermore, optical calculations demonstrated exceptionally high absorption coefficients (reaching the (Formula presented.) range) in the ultraviolet-visible spectrum. Thermoelectric analysis yielded outstanding peak Figure of Merit (ZT) values of 0.69 for Cs2VCl6, 0.95 for Cs2VBr6, and 1.96 for Cs2Vl6 at high temperature. Consequently, these quantitative findings strongly demonstrate that Cs2VCl6, Cs2Vl6, and Cs2VBr6 possess tremendous potential for next-generation spintronic, optoelectronic, and thermoelectric device integration.