Electronic structure of the Cu₂MnAl Heusler alloy

Abstract

The electronic structure and chemical bonding mechanism of the Heusler alloy Cu2 MnAl are studied on the basis of band-structure calculations, using the full-potential linearized augmented-plane-wave (FLAPW) method. The calculations are performed within both the local spin-density approximation (LSDA) and the generalized gradient approximation (GGA). The calculated band structures and the densities of states within the GGA are compared with the earlier-reported experimental results of ultraviolet photoemission spectroscopy. The comparisons support the physical picture proposed by Kübler and co-workers, in which the occupied d states of Mn are delocalized by their strong interaction with the d states of Cu. The magnetic Compton profiles (MCPs) are also calculated and compared with the earlier-reported experimental results. The comparisons show that the GGA is better able to reproduce the experimental profiles than the LSDA. The spin moment on the Mn site is calculated to be 3.20 µB , which is in agreement with the value deduced from the experimental profiles.

Spin-Resolved Fermi Surface of the Localized Ferromagnetic Heusler CompoundCu2MnAlMeasured with Spin-Polarized Positron Annihilation

“…The generalized gradient approximation (GGA) was used to approximate the exchange-correlation functional [38], and the resulting band structure was found to be in reasonable agreement with previous calculations [39,40]. The calculated spin moment was 3.51 μ B =f:u: In order to simulate the slightly reduced spin magnetic moment at room temperature [15], calculations were also performed at a fixed spin moment of 3.2 μ B =f:u:.…”

The Electronic Structure and Magnetic Properties of Full- and Half-Heusler Alloys

“…The minority-spin electrons of Mn are not occupied in these alloys as in Cu 2 MnAl alloy. 8,13) We would like to point out Fig. 2.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] The ferromagnetic martensites are experimentally found in different Heusler alloys such as Ni-Mn-Ga, Ni-Fe-Ga, CoNi-Ga and other alloys. The magnetic shape memory effect is related to martensite transformations that are sensitive to pronounced magnetoelastic interaction.…”

“…For example Mn-based compounds demonstrate rather localized magnetism due to configuration of Mn d-orbitals, 9,13,17) whereas Co-based compounds show more itinerant behavior. 18,19) So-called full-Heusler alloys with a general formula unit of X 2 YZ, where X and Y denote the transition metals and Z is s-p element such as Al, Ga, Sn, Sb, etc., are studied also with respect to the transition from the ferromagnetic phase to an antiferromagntic one with changing of the concentration of the carriers.…”

Co2FeAl based magnetic tunnel junctions with BaO and MgO/BaO barriers

“…1 Moreover, the theoretical prediction of 100% spin polarization for an entire class of materials, the half-Heusler XYZ [2][3][4][5] as well as the full-Heusler X 2 YZ [6][7][8][9] alloys is currently the driving force for spintronic applications in form of thin film devices such as magnetic tunneling junctions (MTJ). In the structural formulae X and Y denote transition metal elements and Z is a group III, IV, or V element.…”