Anomalous Hall Effect and Magnetoresistance in Mn-Doped ZnSnAs₂ Epitaxial Film on InP Substrates

Abstract

We present for the first time the temperature dependence of resistivity, anomalous Hall effect, and extraordinary magnetoresistance (MR) in 6.5% Mn-doped ZnSnAs2 epitaxial film prepared by molecular beam epitaxy (MBE) on InP(001) substrates. The magnetic field dependence of magnetization (M–H curve) show clear hysteresis loops at 300 K for magnetic fields applied both perpendicular and parallel to the sample surface. The Curie temperature was evaluated to be 350 K. Near-zero-field hysteresis loops in the anomalous Hall resistance were also observed at various temperatures corresponding to the hysteretic out-of-plane magnetization of the sample. Negative and positive values of MR were observed in the low-field region. The behavior of the MR can be properly described by the Khosla–Fischer semi-empirical model for spin scattering of carriers in an impurity band. These characteristics strongly indicate a carrier-spin interaction in Mn-doped ZnSnAs2.

Defect-band mediated ferromagnetism in Gd-doped ZnO thin films

“…The first term in Eq. (2) indicates negative MR, 44,45 which accounts for the spin-dependent scattering of localized electrons in the impurity band and weaken as the field-induced spin-polarization progresses. Therefore, negative MR shows the presence of an impurity band in these films.…”

“…Therefore, negative MR shows the presence of an impurity band in these films. 44,45 The second term accounts primarily for the positive MR, which is related to two-band conduction (via CB and impurity-O defect band). The negative scattering is found to be dominant in all the thin films below 50 K, which is an indication of spontaneous spin-polarization of localized spins at the isolated paramagnetic ions 46 (Gd 3þ in the present case).…”

Ferromagnetic and transport properties of p‐type (Zn,Mn,Sn)As2thin films grown on InP substrates for various Mn contents

“…More recently, ternary ferromagnetic II-IV-V 2 compounds crystallizing in the chalcopyrite structure are of special interest for potential applications in spintronic devices, owing to their roomtemperature ferromagnetism [4][5][6]. Among the II-IV-V 2 chalcopyrites, we have proposed a Mn-doped ZnSnAs 2 thin film showing ferromagnetism at room temperature as a ferromagnetic building block in InP-based spintronics [7][8][9]. ZnSnAs 2 is a member of the II-IV-V 2 pnictide semiconductors, these kinds of thin films are known to crystallize into either chalcopyrite or sphalerite structures depending on the growth conditions [10].…”

XAFS studies of diluted magnetic semiconductor Mn-doped ZnSnAs2thin films on InP substrates

“…Using the optimum substrate temperature of 300 °C and a Zn:Sn:As 4 beam equivalent pressure (BEP) ratio of 24:1:52, we grew a 100-nm-thick ZnSnAs 2 epitaxial film doped with 5.0% or 6.5% Mn on a 16-nm ZnSnAs 2 buffer layer. The detailed growth procedure of ZnSnAs 2 :Mn films on InP (001) has been published [9][10]. High-resolution X-ray diffraction (HR-XRD) measurements were performed to determine the lattice constant of the samples.…”

“…The magnetic ion Mn, which occupies the cation IV site in host chalcopyrite or zinc-blende (sphalerite) structures, has a local spin and at the same time acts as an acceptor. Very recently, ZnSnAs 2 :Mn thin films have been epitaxially grown on InP (001) without any secondary phases, and have shown room-temperature ferromagnetism [8][9][10]. Both experimentally and theoretically, ZnSnAs 2 is probably regarded as a "vertical GaAs" to some extent, consisting of two interposing zincblende lattices, while permitting a high degree of Mn incorporation because Mn 2+ ions may easily substitute on the group II Zn sites.…”