Spin polarization studies in half-metallic Co2TiX (X = Ge and Sn) Heusler alloys

TL;DR

This study investigates the structural, magnetic, and spin polarization properties of Co2TiX (X=Ge, Sn) Heusler alloys, revealing high spin polarization and Curie temperatures, indicating their potential for spintronic applications.

Contribution

The paper provides experimental evidence of high spin polarization and Curie temperatures in Co2TiX alloys, demonstrating their suitability for spintronic devices, which is a novel application of these materials.

Findings

Spin polarization values of 0.63 and 0.64 for Co2TiGe and Co2TiSn.

Curie temperatures of 384 K and 371 K for Co2TiGe and Co2TiSn.

Alloys exhibit L21 crystal structure with high potential for spintronics.

Abstract

In this paper, we investigated the Co2TiX (X = Ge, Sn) Heusler alloys by structural, magnetic and spin polarization measurements to probe the half-metallic nature. Alloys are synthesized using the arc melting technique, and found to exist in L21 crystal structure with Fm-3m space group. Curie temperature (TC) is found to be 384 and 371 K for Co2TiGe and Co2TiSn respectively. The saturation magnetization (MS) value of 1.8 and 2.0 Bohr magneton/f.u. are obtained at 5 K for for Co2TiGe and Co2TiSn respectively, compared to 2.0 Bohr magneton/f.u. calculated by Slater-Pauling rule. To obtain the spin polarization value, differential conductance curves are recorded at the ferromagnetic/superconducting point contact at 4.2 K. The current spin polarization (P) value of 0.63 and 0.64 are deduced for Co2TiGe and Co2TiSn respectively. Considering the high current spin polarization and TC, these materials appear to be promising for spintronic devices.