Mohamed El Amine El Goutni , Hela Ferjani , Mohammed Batouche , Taib Seddik
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引用次数: 0
Abstract
In this study, the structural, electronic, optical, and magnetic properties of vacancy-ordered double perovskites Cs2ReX6 (X = Cl, Br, I) are investigated using density functional theory (DFT). GGA + mBJ calculations yield band gaps of 2.68 eV (Cl), 2.19 eV (Br), and 1.40 eV (I). The valence band maximum (VBM) potentials decrease from +2.54 V to +1.88 V and +1.11 V versus the normal hydrogen electrode (NHE), while the conduction band minimum (CBM) values are −0.14 V, −0.31 V, and −0.29 V, respectively. These trends are influenced by increasing halogen ionic radius and decreasing electronegativity. Mechanical stability is confirmed through elastic constants, and all compounds show ductile behavior. Cs2ReI6 exhibits enhanced infrared absorption and the highest dielectric constant (ε1(∞) = 7.62), indicating strong optical response in the IR region. Magnetic calculations reveal a ferromagnetic ground state for all compounds, with total magnetic moments close to 3 μB, mainly contributed by Re 5d electrons. The combination of favorable band edge positions, stable ferromagnetism, and strong light absorption suggests that Cs2ReX6 materials are promising candidates for photocatalysis, optoelectronics, and spintronic devices.
期刊介绍:
The Journal of Physics and Chemistry of Solids is a well-established international medium for publication of archival research in condensed matter and materials sciences. Areas of interest broadly include experimental and theoretical research on electronic, magnetic, spectroscopic and structural properties as well as the statistical mechanics and thermodynamics of materials. The focus is on gaining physical and chemical insight into the properties and potential applications of condensed matter systems.
Within the broad scope of the journal, beyond regular contributions, the editors have identified submissions in the following areas of physics and chemistry of solids to be of special current interest to the journal:
Low-dimensional systems
Exotic states of quantum electron matter including topological phases
Energy conversion and storage
Interfaces, nanoparticles and catalysts.