Perpendicular compensated ferrimagnetic tunnel junctions

Abstract

Combining the advantages of ferromagnetic and antiferromagnetic tunnel junctions, ferrimagnetic tunnel junctions are highly desirable for spintronic applications. Here, we design and experimentally demonstrate a novel type of perpendicular compensated ferrimagnetic tunnel junction composed of the ferrimagnetic oxide NiCo₂O₄ and the compensated ferrimagnetic alloy Co_100-xGd_x separated by an MgAl₂O₄ insulating barrier. The tunneling magnetoresistance undergoes a sign transition from positive to negative (from +72% to -22%) as the temperature increases across the magnetization compensation point of Co_100-xGd_x, which is attributed to the reversible magnetic dominance between the Co and Gd sublattices. Furthermore, we employ this ferrimagnetic tunnel junction to realize temperature-dependent non-volatile multilevel states. Our findings on the perpendicular compensated ferrimagnetic tunnel junctions can provide an attractive avenue for developing ferrimagnet-based devices.

Keywords

Ferrimagnetic tunnel junctions / perpendicular magnetic anisotropy / non-volatile

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