The composition dependence of the tunnel magnetoresistance (TMR) effect in Mn-Ga/MgO/CoFe magnetic tunnel junctions (MTJs) for Mn54Ga 46, Mn62Ga38, and Mn71Ga 29 (at. %) electrodes was investigated. An MTJ with a Mn 62Ga38 electrode showed a maximum TMR ratio of 23% at 10 K and high annealing endurance up to 375 °C. The bias voltage dependence of the TMR ratio was distinct among MTJs with different Mn-Ga compositions. Here, we discuss this dependence on the basis of the difference in the Δ1 band dispersions for Mn-Ga alloys calculated by first principles.
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