[20a-W241-1~12] 10.3 Giant magnetoresistance (GMR), tunnel magnetoresistance (TMR) and magnetic recording technologies

▲ [20a-W241-2] Large tunnel magnetoresistance in Co₂FeAl/MgAl₂O₄/Co₂FeAl junctions free from the band folding effect

〇(D)Thomas Scheike^1,2, Hiroaki Sukegawa², Koichiro Inomata², Tadakatsu Ohkubo², Kazuhiro Hono^1,2, Seiji Mitani^1,2 (1.Tsukuba Univ., 2.NIMS)

Keywords:TMR,MTJ,Heusler

Recently, we reported the fabrication of lattice-matched Heusler electrode Co₂FeAl (CFA)/CoFe insertion/cation-disordered MgAl₂O₄/CoFe junctions and observed a relatively large tunnel magnetoresistance (TMR) ratio up to 281% at room temperature (RT). However, a large TMR ratio (exceeding 200%) using cation-ordered spinel barrier was yet to be achieved. In this talk, we show a large TMR ratio up to 342% at RT using a cation-ordered MgAl₂O₄ barrier and highly spin-polarized CFA top- and bottom-electrodes. The large TMR ratio in an ordered spinel barrier magnetic tunnel junction may be attributed to the achievement of nearly half-metallic CFA layers for both electrodes, which may effectively suppress the so-called band-folding effect.