The structural, elastic, electronic, magnetic and optical properties of the Zn0.75V0.25X (X = S, Se or Te)

The structural, elastic, electronic, magnetic and optical properties of the Zn0.75V0.25X (X = S, Se or Te) have been investigated by the spin-polarized first-principles calculations. The optimized lattice constant increases with the increasing anions radius of S2−, Se2− and Te2−. All the Zn0.75V0.25X systems show the ductile and half-metallic characters. The spin exchange splitting energy Δx(d)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\Delta _x}(d)$$\end{document} increases but the absolute value of the exchange splitting energy Δx(pd)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\Delta _x}(pd)$$\end{document} decreases for Zn0.75V0.25S, Zn0.75V0.25Se and Zn0.75V0.25Te successively, and the p–d exchange constant N0β\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${N_0}\beta$$\end{document} is greater than s–d exchange constant N0α\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${N_0}\alpha$$\end{document}. The static dielectric constants ε1(0)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\varepsilon _1}(0)$$\end{document}, the maximum value of ε2(ω)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\varepsilon _2}(\omega )$$\end{document}, static refractive indexes n(0)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$n(0)$$\end{document} and the maximum value of k(ω)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$k(\omega )$$\end{document} get the biggest values for Zn0.75V0.25Se among Zn0.75V0.25X (X = S, Se or Te). Compared with pure ZnX, the new absorption peaks occur in the energy range of 0–1.4 eV for Zn0.75V0.25X systems. The results provide a certain degree of helpful theoretical guidance for the application of the Zn0.75V0.25X in spintronics devices and optical detectors.