High spin polarization and large spin splitting in equiatomic quaternary CoFeCrAl Heusler alloy

Abstract

In this paper, we investigate CoFeCrAl alloy by means of various experimental techniques and ab-initio calculations to look for half-metallic nature. The alloy is found to exist in the cubic Heusler structure, with presence of B2 ordering. Saturation magnetization (MS) value of about 2 Bohr magneton/f.u. is observed at 8 K under ambient pressure, which is in good agreement with the Slater-Pauling rule. MS values are found to be independent of pressure, which is a prerequisite for half-metals. The ab-initio electronic structure calculations predict half-metallic nature for the alloy with a spin slitting energy of 0.31 eV. Importantly, this system shows a high current spin polarization value of 0.67 [with error of 0.02], as deduced from the point contact Andreev reflection (PCAR) measurements. Linear dependence of electrical resistivity with temperature indicates the possibility of reasonably high spin polarization at elevated temperatures (~150 K) as well. All these suggest that CoFeCrAl is a promising material for the spintronic devices.

11 pages, 5 figures, regular article

References in corpus (3)

• Spin gapless semiconducting behavior in equiatomic quaternary CoFeMnSi Heusler alloy
• A New Spin Gapless Semiconductors Family: Quaternary Heusler Compounds
• High spin polarization in CoFeMnGe quaternary Heusler alloy

Cited by in corpus (8)

• Electronic structure, magnetism and antisite disorder in CoFeCrGe and CoMnCrAl quaternary Heusler alloys
• Half-metallic Ferromagnets, Spin Gapless Semiconductors, and Topological Semimetals Based on Heusler Alloys
• Prediction of half-metallicity and spin-gapless semiconducting behavior in the new series of FeCr-based quaternary Heusler alloys: an ab initio study
• Magnetic tunnel junctions with a B2-ordered CoFeCrAl equiatomic Heusler alloy
• Systematic understanding of half-metallicity of ternary compounds in Heusler and Inverse Heusler structures with 3$d$ and 4$d$ elements
• High spin-polarization in a disordered novel quaternary Heusler alloy FeMnVGa
• Magnetic properties of low-moment ferrimagnetic Heusler Cr2CoGa thin films grown by molecular beam epitaxy
• Vanishing of the anomalous Hall effect and enhanced carrier mobility in the spin-gapless ferromagnetic Mn2CoGa1-xAlx alloys