Interfacial giant tunnel magnetoresistance and bulk-induced large perpendicular magnetic anisotropy in (111)-oriented junctions with fcc ferromagnetic alloys: A first-principles study

Abstract

We study the tunnel magnetoresistance (TMR) effect and magnetocrystalline anisotropy in a series of magnetic tunnel junctions (MTJs) with $L{1}_1$-ordered fcc ferromagnetic alloys and MgO barrier along the [111] direction. Considering the (111)-oriented MTJs with different $L{1}_1$ alloys, we calculate their TMR ratios and magnetocrystalline anisotropies on the basis of the first-principles calculations. The analysis shows that the MTJs with Co-based alloys (CoNi, CoPt, and CoPd) have high TMR ratios over 2000$\%$. These MTJs have energetically favored Co-O interfaces where interfacial antibonding between Co $d$ and O $p$ states is formed around the Fermi level. We find that the resonant tunneling of the antibonding states, called the interface resonant tunneling, is the origin of the obtained high TMR ratios. Our calculation of the magnetocrystalline anisotropy shows that many $L{1}_1$ alloys have large perpendicular magnetic anisotropy (PMA). In particular, CoPt has the largest value of anisotropy energy $K_{\mathrm{u}}\approx 10MJ/{\mathrm{m}}^3$. We further conduct a perturbation analysis of the PMA with respect to the spin-orbit interaction and reveal that the large PMA in CoPt and CoNi mainly originates from spin-conserving perturbation processes around the Fermi level.

arXiv comment11 pages, 9 figures, 2 tables

References in corpus (10)

• First-principles investigation of the very large Perpendicular Magnetic Anisotropy at Fe|MgO Interfaces
• Ballistic conductance of magnetic Co and Ni nanowires with ultrasoft pseudo-potentials
• Anatomy of perpendicular magnetic anisotropy in Fe/MgO magnetic tunnel junctions: First principles insight
• MgO barrier-perpendicular magnetic tunnel junctions with CoFe/Pd multilayers and ferromagnetic insertion layers
• Origin of perpendicular magneto-crystalline anisotropy in L10-FeNi under tetragonal distortion
• Anatomy of interfacial spin-orbit coupling in Co/Pd multilayers using X-ray magnetic circular dichroism and first-principles calculations
• Perpendicular magnetic anisotropy at the Fe/MgAl${}_2$O${}_4$ interface: Comparative first-principles study with Fe/MgO
• Detecting quadrupole: a hidden source of magnetic anisotropy for Manganese alloys
• Bias voltage effects on tunneling magnetoresistance in Fe/MgAl${}_2$O${}_4$/Fe(001) junctions: Comparative study with Fe/MgO/Fe(001) junctions
• Interface-driven giant tunnel magnetoresistance in (111)-oriented junctions

Cited by in corpus (3)

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• Band-folding-driven high tunnel magnetoresistance ratios in (111)-oriented junctions with SrTiO${}_3$ barriers
• Theory of tunnel magnetoresistance in magnetic tunnel junctions with hexagonal boron nitride barriers: mechanism and application to ferromagnetic alloy electrodes