A 4-fold-symmetry hexagonal ruthenium for magnetic heterostructures exhibiting enhanced perpendicular magnetic anisotropy and tunnel magnetoresistance

Abstract

An unusual crystallographic orientation of hexagonal Ru with a 4-fold symmetry emerging in epitaxial MgO/Ru/Co2FeAl/MgO heterostructures is reported, in which an approximately Ru(02-23) growth attributes to the lattice matching among MgO, Ru, and Co2FeAl. Perpendicular magnetic anisotropy of the Co2FeAl/MgO interface is substantially enhanced as compared with those with a Cr(001) layer. The MTJs incorporating this structure gave rise to the largest tunnel magnetoresistance for perpendicular MTJs using low damping Heusler alloys. The 4-fold-symmetry hexagonal Ru arises from an epitaxial growth with an unprecedentedly high crystal index, opening a unique pathway for the development of perpendicular anisotropy films of cubic and tetragonal ferromagnetic alloys.

arXiv commentAdvanced Materials 2014

References in corpus (2)

• First-principles investigation of the very large Perpendicular Magnetic Anisotropy at Fe|MgO Interfaces
• Multifunctional L10-Mn1.5Ga films with ultrahigh coercivity, giant perpendicular magnetocrystalline anisotropy and large magnetic energy product

Cited by in corpus (10)

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• Interdiffusion in epitaxial ultrathin Co2FeAl/MgO heterostructures with interface-induced perpendicular magnetic anisotropy
• Tunable magnetization relaxation of Fe_{2}Cr_{1-x}Co_{x}Si half-metallic Heusler alloys by band structure engineering
• Evolution of the interfacial perpendicular magnetic anisotropy constant of the Co${}_2$FeAl/MgO interface upon annealing
• Perpendicular magnetic anisotropy in Co${}_2$Fe${}_{0.4}$Mn${}_{0.6}$Si
• Spin-orbit torques and magnetization switching in perpendicularly magnetized epitaxial Pd/Co2FeAl/MgO structures
• First-principles investigation of magnetocrystalline anisotropy oscillations in Co${}_2$FeAl/Ta heterostructures