Designing new ferromagnetic double perovskites: the coexistence of polar distortion and half-metallicity

Advancing technology and growing interdisciplinary fields raise the need for new materials that simultaneously possess several significant physics quantities to meet human demands. In this research, using density functional theory, we aim to design A₂MnVO₆ (A = Ca, Ba) as new double perovskites and investigate their structural, electronic, and magnetic properties. Structural calculations based on the total energies show the optimized monoclinic and orthorhombic crystal structures for the Ca₂MnVO₆ (CMVO) and Ba₂MVO₆ (BMVO) compounds, respectively. Through performing calculations, we reveal that the Jahn-Teller effect plays an important role in polar distortions of VO₆ and elongation of MnO₆ octahedra, resulting from the V⁵⁺(3d⁰) and Mn³⁺(3d⁴:t32ge1g) electron configurations. The spin-polarized calculations predict the half-metallic ferromagnetic ground state for CMVO and BMVO with a total magnetic moment of 4.00 μ_B f.u.^-1 Our findings introduce CMVO and BMVO double perovskites as promising candidates for designing ferromagnetic polar half-metals and spintronic applications.