Electronic, Elastic and X-ray spectroscopic properties of direct and inverse full Heusler compounds: DFT+U study

TL;DR

This study uses DFT+U calculations to analyze the electronic, elastic, and X-ray spectroscopic properties of Co2FeAl and Fe2CoAl full Heusler compounds, revealing their half-metallic and metallic behaviors and matching experimental magnetic data.

Contribution

It provides a detailed DFT+U analysis of Fe2CoAl, a less understood inverse Heusler compound, and compares its properties with the well-studied Co2FeAl.

Findings

Co2FeAl exhibits half-metallicity; Fe2CoAl is metallic.

Calculated magnetic moments and Curie temperatures agree with experiments.

GGA+U improves the understanding of valence electron effects.

Abstract

Half-metallicity, low magnetic damping and high curie temperature (TC) are crucial for application in spintronics and full Heusler alloys in this regard exhibit remarkable properties. Herein, we have considered Co2FeAl (CFA) and Fe2CoAl (FCA) as a representative of direct and indirect full Heusler compounds which crystallises in L21 and C1b phases, respectively. The theory of L21 type Heusler alloys has been well established, however the fundamental understanding of Fe2CoAl is still under developed. In this paper, we have employed density functional theory (DFT) to study the electronic, elastic and X-ray spectroscopic properties of Co2FeAl and Fe2CoAl. The electron exchange correlation were treated within a generalized gradient approximation (GGA) as PBE-scheme. In order to include the impact of valence electrons an onsite Coulomb potential is added to GGA as GGA+U. Within both GGA and GGA+U, CFA shows a half-metallic behaviour but FCA is metallic. The calculated values of magnetic moment and TC are in close agreement with the experimental data.