Electronic, magnetic and galvanomagnetic properties of Co-based Heusler alloys: possible states of a half-metallic ferromagnet and spin gapless semiconductor

TL;DR

This paper investigates the electronic, magnetic, and galvanomagnetic properties of Co-based Heusler alloys, exploring their potential as half-metallic ferromagnets and spin gapless semiconductors for spintronics applications.

Contribution

It analyzes how the properties of Co$_2$YSi and Co$_2$MnZ alloys vary in different magnetic states, revealing correlations with valence electrons and spin polarization.

Findings

Significant changes in magnetization and resistivity were observed.

Correlations between electronic/magnetic properties and valence electrons were established.

Possible states of HMF and SGS were identified in the alloys.

Abstract

Parameters of the energy gap and, consequently, electronic, magnetic and galvanomagnetic properties in different X$_2$YZ Heusler alloys can vary quite strongly. In particular, half-metallic ferromagnets (HMFs) and spin gapless semiconductors (SGSs) with almost 100% spin polarization of charge carriers are promising materials for spintronics. The changes in the electrical, magnetic and galvanomagnetic properties of the Co$_2$YSi (Y = Ti, V, Cr, Mn, Fe) and Co$_2$MnZ Heusler alloys (Z = Al, Si, Ga, Ge) in possible HMF and/or SGS states were followed and their interconnection was established. Significant changes in the values of the magnetization and residual resistivity were found. At the same time, the correlations between the changes in these electronic and magnetic characteristics depending on the number of valence electrons and spin polarization are observed.