Chemically induced ferromagnetism near room temperature in single crystal (Zn1-x Cr x )Te half-metal.

Abstract

Magnetic semiconductors are at the core of recent spintronics research endeavors. Chemically doped II-VI diluted magnetic semiconductors, such as (Zn1-x Cr x )Te, provide a promising platform in this quest. However, a detailed knowledge of the microscopic nature of magnetic ground state is necessary for any practical application. Here, we report on the synergistic study of (Zn1-x Cr x )Te single crystals using elastic neutron scattering measurements and density functional calculations. For the first time, our research unveils the intrinsic properties of ferromagnetic state in a macroscopic specimen of (Zn0.8Cr0.2)Te. The ferromagnetism is onset at T C ∼ 290 K and remains somewhat independent to modest change in the substitution coefficient x. We show that magnetic moments on Zn/Cr sites develop ferromagnetic correlation in the a-c plane with a large ordered moment of μ = 3.08 μ B. Magnetic moment across the lattice is induced via the mediation of Te sites, uncoupled to the number of dopant carriers as inferred from the density functional calculation. Additionally, the ab initio calculations also reveal half-metallicity in x = 0.2 composition. These properties are highly desirable for future spintronic applications.