Preserving the half-metallicity at the surfaces of rocksalt CaN and SrN and the interfaces of CaN/InN and SrN/GaP: a density functional study

The search for ferromagnetic semiconductors and stable half-metallic ferromagnets remains a high priority in solid-state physics. A general understanding of structureproperty relationships is a necessary prerequisite for the design of new materials. In this study, the band structures and magnetic properties of the form XCaZ (Y = Ca) compounds in the half-Heusler structure have been calculated with the full-potential linear augmented plane wave (FP-LAPW) method within the spin density functional theory. The calculations reveal that the nonmagnetic element can induce stable ferromagnetic state in alkaline metals. The most stable atomic arrangement is when XCaZ occupy the (0, 0, 0), (1/4, 1/4, 1/4) and (3/4, 3/4, 3/4) positions. For the majority spin channel the Fermi level is located in the band gap, and for the minority spin there is no energy gap around the Fermi level, which gives a direct evidence of the half-metallic behavior.

Section: Structural Propertiesmentioning

confidence: 99%

Half-Metallicity Ferromagnetism in Half-Heusler XCaZ (X = Li, Na; Z = B, C) compounds: an Ab Initio Calculation

Benabboun

Mesri

Tadjer

et al. 2015

“…HM ferromagnets without transition metals have a small magnetic moment and may be more preferable in spintronic device applications because of their low stray fields and energy loss. There are several theoretical studies which predicted HM characteristic in ferromagnets without transition metals, such as, the graphene nanoribbon [35], the alkaline-earth carbides, and nitrides with zinc-blende and rocksalt structures [36][37][38][39][40][41]. Some studies have also confirmed the HM nature of these compounds, experimentally [42].…”

Section: Introductionmentioning

confidence: 95%

First-Principles Study of Half-Metallic Ferromagnetism of the Full-Heusler Compounds RbSrX2 (X = C, N, and O)

Bagverdi

Ahmadian

2015

First-principles calculations based on density functional theory (DFT) for RbSrX 2 (X = C, N, and O) Heusler compounds were performed using the selfconsistent full-potential linearized augmented plane wave (FPLAPW) method. The results showed that the ground state of all three compounds in ferromagnetic state was the AlCu 2 Mn-type structure. The RbSrC 2 in the AlCu 2 Mntype and CuHg 2 Ti-type structures was a nonmagnetic metal, while RbSrN 2 and RbSrO 2 compounds in both structures were half-metallic ferromagnets. The calculated majority band gaps for RbSrN 2 and RbSrO 2 compounds in the AlCu 2 Mn-type (CuHg 2 Ti-type) structure were 5.3 (2.7) and 4.7 (3.4) eV, respectively. The origin of majority band gaps was also studied using the band structure calculations and density of states (DOSs). The total magnetic moment of RbSrN 2 and RbSrO 2 compounds were respectively obtained 3 and 1 μ B per formula unit at the equilibrium lattice parameter, which were in agreement with Slater-Pauling rule (M tot = 12 − Z tot ). The RbSrN 2 and RbSrO 2 compounds respectively maintained their half-metallic characteristic at lattice constants ranges of 5.71-8.82Å (5.73-8.36Å) and 5.64-8.93Å (5.13-8.05Å) for AlCu 2 Mn-type (CuHg 2 Titype) structure, indicating that the lattice distortion did not affect the half-metallic properties of the compounds, which makes them interesting materials in the spintronic field.

“…Furthermore, it is necessary to find HM compounds without transition metals which are called sp or d 0 half-metals. There are a few theoretical studies on d 0 ferromagnets such as the graphene nanoribbon [41], the alkaline-earth carbides, and the nitrides with zinc-blende and rock-salt structures [42][43][44][45][46][47] in which half-metallicity has been predicted. Experimental studies have also confirmed the HM nature for some of these compounds [48].…”

Section: Introductionmentioning

confidence: 99%

Robust Half-Metallicity and Electronic Structure of the New Full-Heusler Compounds CsBaX2 (X = C, N, and O)

Erfan

Ahmadian

2015

The electronic structure and magnetism of new Heusler alloys of CsBaX 2 (X = C, N, and O) were investigated within density functional theory (DFT) using the selfconsistent full-potential linearized augmented plane wave (FPLAPW) method. The CsBaC 2 in the AlCu 2 Mn-type was a half-metallic ferromagnet while it was a nonmagnetic metal in CuHg 2 Ti-type structure. CsBaN 2 and CsBaO 2 compounds in both structures were half-metallic ferromagnets. The majority band gap for CsBaC 2 in the AlCu 2 Mntype was obtained equal to 1.67 eV and for CsBaN 2 and CsBaO 2 compounds in the AlCu 2 Mn-type (CuHg 2 Ti-type) structure were calculated equal to 2.34 (2.29) eV and 3.53 (2.76) eV, respectively. The origin of half-metallicity was also studied using the band structure calculations and density of states (DOSs). The total magnetic moments of CsBaC 2 , CsBaN 2 , and CsBaO 2 compounds were, respectively, obtained as 5μ B , 3μ B , and 1μ B per formula unit at the equilibrium lattice parameter, which were in agreement with Slater-Pauling rule (M tot = 12-Z tot ). The CsBaX 2 (X = C, N, and O) compounds kept their half-metallic characteristic in a wide range of lattice constants in comparison with Heusler alloys including transition metals, which makes them promising and attractive materials in spintronic field.