Phase stability, magnetism and generalized electron-filling rule of vanadium-based inverse Heusler compounds

Abstract

By using first-principles calculations, we have systematically investigated the phase stability, magnetism and electron-filling behavior of vanadium-based inverse Heusler compounds. Our calculation results indicate that, due to the complex hybridization of the d orbitals for the vanadium atom, the electronic structures of the vanadium-based inverse Heusler compounds show two opened gaps (one locates in the spin-up channel and the other in the spin-down channel) near the Fermi level, originating from different bonding states. Based on the unique electronic structures, we proposed a generalized electron-filling rule, which can qualitatively explain the unusual change of the molecular spin magnetic moment as a function of the total number of valence electrons observed in the vanadium-based inverse Heusler compounds. Moreover, most of the vanadium-based inverse Heusler compounds have a negative formation energy, which indicates that they are promising to be synthesized experimentally.

Largest Magnetic Moments in the Half-Heusler Alloys XCrZ (X = Li, K, Rb, Cs; Z = S, Se, Te): A First-Principles Study

“…Damewood et al found that these LiMnZ (Z = N, P, Si) alloys show HM behaviors with large semiconducting-type band-gaps and magnetic moments (>3 μ B per formula unit) at their strained lattice constants. To our best knowledge, based on the the Slater-Pauling (S-P) and generalized electron-filling rules [ 17 , 18 , 19 , 20 ], the largest magnetic moment of the half-Heusler-type alloy should be 5 μ B per formula unit. Due to the large semiconducting-type band-gaps and the large magnetic moments, LiMnZ (Z = N, P, Si) alloys may be good candidates for spintronic materials for devices operating at or above room temperature.…”

L21 and XA Ordering Competition in Hafnium-Based Full-Heusler Alloys Hf2VZ (Z = Al, Ga, In, Tl, Si, Ge, Sn, Pb)

“…Moreover, from the obtained total DOS, we calculated the spin polarization ( p ) at Fermi energy of XA and L2 1 types Hf 2 VZ. The spin polarization p (%) that can be defined as the ratio of the difference to sum of the DOS values of spin up and spin down version at the Fermi-level [ 13 , 16 ], represented by mathematical formulation as a percent; where the n ↑ ( E f ) and n ↓ ( E f ) stand for the spin-dependent DOS around the Fermi level. The results have been given in Table 3 , we can see that the p of XA-type Hf 2 VZ are quite high (>88%), even some alloys (such as Hf 2 VAl) have completely spin polarization (100%).…”

“…Heusler alloys are a noticeable class of intermetallic materials that represent as usual by the formula X 2 YZ (often called full-Heusler) [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ] or XYZ (usually named as half-Heusler) [ 16 ], where X, Y are transition-metal-element atoms and Z is a main group element. The structure of full-Heusler alloys consists of four interpenetrating fcc lattices with four equidistant sites as basis along the diagonal of the unit cell.…”

“…The structure of full-Heusler alloys consists of four interpenetrating fcc lattices with four equidistant sites as basis along the diagonal of the unit cell. According to the well-known Site Preference Rule (SPR) [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ], when the valence of the X is larger than that of Y, the atomic sequence is X A -Y B -X C -Z D and the structure is the well-known L2 1 one with prototype Cu 2 MnAl. Otherwise, the alloys crystallize in the so-called XA structure, where the sequence of the atoms is then X A -X B -Y C -Z D and the prototype is Hg 2 CuTi.…”

Rare earth-based quaternary Heusler compoundsMCoVZ(M= Lu, Y;Z= Si, Ge) with tunable band characteristics for potential spintronic applications

“…That is, an e u -t 1u band gap is created in the spin-up channel. Based on the generalized electron-filling rule (Zhang, Xu et al, 2013;, for MCoVZ the total numbers of occupied states are 12 and 9 in the spin-up and spin-down channels, respectively, and therefore there is a total spin magnetic moment of 3 m B .…”