Epitaxial Heusler alloy Co2FeSi∕GaAs(001) hybrid structures

Abstract

We found that Co 2 FeSi layers on GaAs͑001͒ grown by molecular-beam epitaxy with high crystal and interface perfection as well as smooth surfaces can be obtained in the low-growth-temperature regime. The layers are thermally robust up to 250°C. They have long-range order and crystallize in the Heusler-type L2 1 structure. The easy axis of magnetization is along the ͓110͔ direction caused by a dominating uniaxial in-plane magnetic anisotropy component which has an easy axis different from that of the magnetocrystalline anisotropy component.

Half-metallic Co-based quaternary Heusler alloys for spintronics: Defect- and pressure-induced transitions and properties

“…11,12 Amongst all systems, HAs are most favorable because of their high Curie temperatures and spin polarization along with the structural compatibility to the conventional wide-gap semiconductors. [13][14][15][16] The conventional HAs have 2:1:1 stoichiometry, i.e., X 2 Y Z (ternary), with ordered L2 1 structure (F m3m, space group #225), where X,Y are d-band metals and Z is a non-magnetic p-block element. A 1:1:1:1 stoichiometric structure arises when one X is replaced by a more or less electronegative, transition metal element, forming a Y -type structure (F43m space group, #216) -or equiatomic quaternary HAs.…”

Magnetoelastic coupling induced magnetic anisotropy in Co2(Fe/Mn)Si thin films

“…Some examples of this are Co 2 MnGe on GaAs (Ref. 3) and Al 2 O 3 , 4 Co 2 MnSi on GaAs, 5 MgO, [6][7][8] and Al 2 O 3 , 9 Co 2 FeAl 0.5 Si 0.5 on MgO, 10 Co 2 FeSi on GaAs, 11,12 Al 2 O 3 , 13 and MgO (Ref. 13) as well as on SrTiO 3 (STO).…”

“…In Heusler alloys films, one expects a four-fold anisotropy due to the cubic symmetry of the unit cell, while in-plane uniaxial anisotropy has also been observed for the case of Co 2 FeSi grown on GaAs. 11 The presence of additional uniaxial anisotropy has resulted in multistep magnetization switching in some Heusler alloy films. 3,5 Moreover, Gabor et al have shown that Co 2 FeAl films can have three types of in-plane anisotropies, namely, biaxial (fourfold cubic anisotropy) and two uniaxial anisotropies parallel to the biaxial easy and hard axes.…”

Perpendicular magnetic anisotropy in the Heusler alloy Co2TiSi/GaAs(001) hybrid structure

“…[14][15][16][17] The intrinsic magnetic anisotropy of the well-known FHA films has been found to be dominated by the in-plane anisotropy. [16][17][18] Very recently, the interface-induced PMA was discovered in a Co-based FHA (Co 2 FeAl) in contact with a MgO oxide layer.…”

“…[14][15][16][17] The intrinsic magnetic anisotropy of the well-known FHA films has been found to be dominated by the in-plane anisotropy. [16][17][18] Very recently, the interface-induced PMA was discovered in a Co-based FHA (Co 2 FeAl) in contact with a MgO oxide layer. 19,20 The proposed explanation for the PMA is similar to that of CoFeB or Fe/MgO systems for which interfacial anisotropy induced by hybridization of Fe-, Co-3d and O-2p orbitals causes the a Electronic email: dau@pdi-berlin.…”