Effect of p-type doped buffer layer on the structural and magnetic properties of (Zn,Fe)Te dilute magnetic semiconductor

Abstract

We have studied the structural and magnetic properties of Zn­_1-xFe_xTe thin films grown under Te-rich flux condition with almost same Fe composition, x = 1.3%, on both undoped and nitrogen (N) acceptor doped ZnTe buffer layer by molecular beam epitaxy (MBE). Structural analysis by XRD and XAFS reveals that Zn­_0.987Fe_0.013Te films are mainly composed of pure diluted phase with substitutional Fe atoms on the Zn-site in the zinc-blende (ZB) ZnTe in both cases. However, the magnetization measurement using SQUID shows distinctly different magnetic properties among these films; a linear dependence of magnetization on magnetic field (M-H), typical of van-Vleck paramagnetic behavior of Zn­_0.987Fe_0.013Te film grown over undoped ZnTe turns into ordinary paramagnetic behavior with S-shape M-H curve for film grown on N-doped ZnTe buffer layer, [N] ≈ 10²⁰ cm^-3 which may reflect the impact of interfacial holes provided by N-acceptors on the valence state of substitutional Fe.

J. Bangladesh Acad. Sci. 48(1); 27-34: June 2024