Conditions for spin-gapless semiconducting behavior in Mn2CoAl inverse Heusler compound

Abstract

Employing ab initio electronic structure calculations, we investigate the conditions for spin-gapless semiconducting (SGS) behavior in the inverse Mn 2 CoAl Heusler compound. We show that tetragonalization of the lattice, which can occur during films growth, keeps the SGS character of the perfect cubic compound. On the contrary, atomic swaps even between sites with different local symmetry destroy the SGS character giving rise to a half-metallic state. Furthermore, the occurrence of Co-surplus leads also to half-metallicity. Thus, we propose that in order to achieve SGS behavior during the growth of Mn 2 CoAl (and similar SGS Heusler compounds) thin films, one should minimize the occurrence of defects, while small deformations of the lattice, due to the lattice mismatch with the substrate, do not play a crucial role. V C 2014 AIP Publishing LLC.

Exploring disorder in the spin gapless semiconductor Mn2CoAl

“…2 displays typical magnetisation hysteresis loops for a Mn2CoAl film collected at 10 K and 300 K. The film has a 10 K saturation magnetisation of 1.02 µB per unit cell, equivalent to 195 emu/cc, which is above the 300 K value by 15%. This is approximately half the expected saturation of 2 µB per unit cell 4,9,10 although as noted in Table I there are reports on films displaying a similar saturation magnetisation near 1 µB.…”

First-principles calculations of exchange interactions, spin waves, and temperature dependence of magnetization in inverse-Heusler-based spin gapless semiconductors

“…45 Finally, recent studies on the effect of doping of Mn 2 CoAl with Co, Cu, V and Ti, 46 as well as the anomalous Hall effect have appeared in literature.…”

Investigation of structural, electronic and magnetic properties of 1:1:1:1 stoichiometric quaternary Heusler alloys YCoCrZ (Z=Si, Ge, Ga, Al): An ab-initio study

“…The discovery of Heusler alloys, marks a great leap forward in the practicability of spintronics. The grandness of Heusler alloys is that, they accomplish the basic needs for spintronics diligence, i.e half-metallicity with effective Curi-temperature (T c ) [1,2].…”