Large perpendicular magnetic anisotropy at Fe/MgO interface

Abstract

A large perpendicular magnetic anisotropy (PMA) of 1.4 MJ/m3 was observed from ultrathin Fe/MgO(001) bilayers grown on Cr-buffered MgO(001). The PMA strongly depends on the surface state of Fe prior to the MgO deposition. A large PMA energy density of 1.4 MJ/m3 was achieved for a 0.7 nm thick Fe layer having adsorbate-induced surface reconstruction, which is likely to originate from oxygen atoms floating up from the Cr buffer layer. This large magnitude of PMA satisfies the criterion that is required for thermal stability of magnetization in a few tens nanometer-sized magnetic memory elements.

Highly efficient voltage control of spin and enhanced interfacial perpendicular magnetic anisotropy in iridium-doped Fe/MgO magnetic tunnel junctions

“…This value is~1.8 times greater than that observed in the pure/MgO interface (2.0 mJ m − 2 ). 35,36 Further doping of Ir leads to a reduction in this value; however, even at t Ir = 0.15 nm, the K i,0 value is still greater than that for the sample without Ir doping. It should be emphasized that no PMA was observed at the Cr/Ir-doped Fe interface (see Supplementary Information S6), similar to the Cr/Fe structure.…”

“…As shown in Figure 2a, we noted PMA in the t Fe range from 0.5 to 0.9 nm for Cr/Fe/MgO; this result is attributed to Fe/MgO interfacial anisotropy. 35,36 The critical thickness of Fe, for which a spin reorientation transition (SRT) from the out-ofplane to in-plane direction occurs, was determined to be 0.9 nm. The Ir doping in the ultrathin Fe layer has a distinct influence on the First, zero-remanence loops for the polar configuration were noted for very thin Fe layers, which indicates that in-plane anisotropy dominates for very thin Fe layers (see also Supplementary Information S3).…”

Interface induced out-of-plane magnetic anisotropy in magnetoelectric BiFeO3-BaTiO3 superlattices

“…Sato 23 succeeded in growing Tb/Fe superlattices with interface-concentrated PMA, whose origin was attributed to the Tb-Fe pairs aligned perpendicular to the films. Recently, interface PMA has been reported in metal/oxide systems like CoFeB-MgO 14 and Fe/MgO 24,25 The enhancement of the out-of-plane magnetic moment component in Fe/MgO was explained by the anisotropic orbital magnetic moments induced by the spin-orbit interaction at the interface. 24 Based on ab initio calculations, Yang et al 26 ascribed the large PMA at Fe/MgO interfaces and O-2p z orbitals at the interface.…”

“…14,[22][23][24][25] For example, Carcia 22 studied Pd/Co and Pt/Co superlattices with an unusual perpendicular anisotropy attributed to an interfacial contribution. Sato 23 succeeded in growing Tb/Fe superlattices with interface-concentrated PMA, whose origin was attributed to the Tb-Fe pairs aligned perpendicular to the films.…”

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

“…PMA. 3,21 For a hybrid structure based on a very thin FHA film (on the order of a few angstroms) coupled with a MgO barrier, a question is whether chemical interactions will alter the electronic band structure of the FHA, (i. e, its spin polarization). Furthermore, film oxidation arising from excess oxygen makes the control of such an interface relatively difficult.…”