High Curie Temperature and Half‐Metallic Ferromagnetism in ZnSe:Co,Ni with Wurtzite Structure: First‐Principles Study

Abstract

Diluted magnetic semiconductors (DMSs) are known as semi-magnetic compounds in which a managed fraction of nonmagnetic cations are replaced by 3d transition metals (TMs). TM 2þ magnetic ions doped II-VI semiconductor compounds are counted as promising optoelectronic materials in the mid-IR region, low energy optical phonon cut-off, and large emission cross-sections. [1,2] The development of Zn-based DMSs II-VI group shows magnificent properties, which have a huge opportunity to be applied in spintronics. [3][4][5][6] These materials have attracted a lot of attention as materials for spintronic applications [7][8][9][10][11][12] because of their half-metallic ferromagnetic (HMFM) behaviors at Curie temperatures higher than room temperature. [13][14][15] These properties were observed in V-, Cr-, and Mn-doped ZnO and ZnTe [16] also in V-, Cr-, and Fe-doped CdTe, [17][18][19] in Cd-and Mn-doped CdS, [20][21][22] and Mn-doped GaAs. [23] In refs. [24][25][26][27][28][29][30][31][32], it was reported that Cr impurities in II-VI semiconductors make FM materials at room temperature.Zinc selenide, a semiconductor, can operate as a half-metallic compound and is a helpful material for optoelectronic and spintronic applications. Zinc selenide is a nonmagnetic material with a direct bandgap of 2.70 eV and has great potential for a diversity of optical and electro-optical devices, such as short wavelength lasers, blue-green laser diodes, pure green lightemitting diodes, microwave and terahertz devices, solar cells and tunable mid-IR laser sources. [33][34][35] TM-doped ZnSe has attracted great research interest as new productive device applicants. , the authors reported that ZnSe:TM was appropriate for applications in spintronics and middle-IR lasing. Sato et al. [26] have predicted high Curie temperatures for Cr-and V-doped zincblende ZnSe, Benstaali et al. [35] in ZnSe:Co, Mohamood et al. [42] in ZnSe:Ti, and Arifet et al. [43] in CdSe:Co reported half-metallic FM due to polarization of the spin in their theoretical study and suggested these are potential candidates for spintronic application, which are in agreement with current work.This work is dedicated to the study of the magnetism in ZnSe: Co and ZnSe:Ni by varying the impurity concentrations for the values x ¼ 12.5% and 6.25%. In the current work, the Curie temperatures are also estimated and obtained that Ni-doped ZnSe compounds are high room temperature materials.The same properties were predicted in current work for TM: ZnSe in the FM and antiferromagnetic (AFM) phases and may be suited as a reference for the FM II-VI DMSs in their alloys and heterostructures.

Ab initio prediction of half-metallic and metallic ferromagnetism in ZnO:(Co,Cr) systems

“…The Curie temperatures of Co x Zn 1−x O and Cr x Zn 1−x O (x = 2.08%, 3.125%, 4.16%, 6.25%, 8.3%, 12.5% and 25%) different size supercell structures were calculated by Mean Field Approximation (MFA) [45] ( )…”