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

Abstract

For theoretical designing of full-Heusler based spintroinc materials, people have long believed in the so-called Site Preference Rule (SPR). Very recently, according to the SPR, there are several studies on XA-type Hafnium-based Heusler alloys X2YZ, i.e., Hf2VAl, Hf2CoZ (Z = Ga, In) and Hf2CrZ (Z = Al, Ga, In). In this work, a series of Hf2-based Heusler alloys, Hf2VZ (Z = Al, Ga, In, Tl, Si, Ge, Sn, Pb), were selected as targets to study the site preferences of their atoms by first-principle calculations. It has been found that all of them are likely to exhibit the L21-type structure instead of the XA one. Furthermore, we reveal that the high values of spin-polarization of XA-type Hf2VZ (Z = Al, Ga, In, Tl, Si, Ge, Sn, Pb) alloys have dropped dramatically when they form the L21-type structure. Also, we prove that the electronic, magnetic, and physics nature of these alloys are quite different, depending on the L21-type or XA-type structures.

Structural, electronic and magnetic properties of MnxGa/Co2MnSi (x = 1, 3) bilayers

“…Thus, the PBE functional should be suitable for the further studies on the electronic and magnetic properties of the MG/CMS bilayers. It can also be seen that the Mn I and Mn II have opposite magnetic moment for D0 3 - and D0 22 -MG bulks, and moreover, D0 3 -MG bulk is fully compensated ferrimagnet due to the spin magnetic moments of Mn I atoms align antiparallelly to those of the Mn II atoms and the total magnet is equal to zero 44 , while D 0 22 -MG bulk is partially compensated ferrimagnet due to the antiparallel spin magnetic moments of Mn I and Mn II atoms and its low saturation magnetization. The L1 0 -MG and L2 1 -CMS bulks are ferromagnets due to the atomic moments of Mn or Co are parallel to each other and they have nonzero net magnetization.…”

Electronic, Magnetic, Half-Metallic, and Mechanical Properties of a New Equiatomic Quaternary Heusler Compound YRhTiGe: A First-Principles Study

“…We examined the formation and cohesive energies of YRhTiGe compound to show the structural stability of this EQH compound. The formation and cohesive energies can be obtained by the following formulae [ 42 , 43 , 44 , 45 ]: where is the YRhTiGe’s total energy for per formula unit, and , , , and are the total energies per atom for each Y, Rh, Ti, and Ge atom in the bulk form, respectively. , , , and are the individual energies of the Y, Rh, Ti, and Ge, respectively.…”

Site-Preference, Electronic, Magnetic, and Half-Metal Properties of Full-Heusler Sc2VGe and a Discussion on the Uniform Strain and Tetragonal Deformation Effects

“…The above parameters ensure the accuracy of the calculated results based on the references [39]. Similar methods to investigate the electronic structures of Heusler alloys can be found in [30][31][32][33].…”

“…For example, Kogachi et al [29] studied the electronic and magnetic properties of Co 2 MnZ (Z = Si, Ge, Sn). Liu et al [30] investigated the electronic structures of Mn 2 CoZ (Z = Al, Si, Ge, Sn, Sb) in detail and found two mechanisms to induce the band gap for minority spin states near the Fermi level; Wang et al [31] studied the electronic and magnetic properties of FH alloy Zr 2 CoZ (Z = Al, Ga, In, Si, Ge, Sn, Pb, Sb) and found that the half-metallicities are robust against lattice distortion; Wang et al also studied the site preferences of the Titanium-based [32] and Hf 2 V-based [33] FH alloys, and found that most of these alloys are likely to form the L2 1 structure instead of the XA structure. Thus, the traditional site-preference rule (SPR) may not be suitable for all FH alloys, such as X 2 YZ, where X is a low-valent transition metal element, such as, Ti, Zr, Sc, and Hf.…”