Co₂Ti_0.5Mn_0.5Al フルホイスラー合金薄膜を用いた強磁性トンネル接合の磁気抵抗効果

抄録

  We investigated the magnetoresistance effect for a magnetic tunnel junction(MTJ) using a Co₂Ti_0.5Mn_0.5Al electrode on a Cr buffered MgO(001) single crystal substrate. The Co₂Ti_0.5Mn_0.5Al formed an ordered L2₁ and B2 structures after post-annealing above 873 K and below 773 K, respectively. Maximum magnetization and minimum coercivity were exhibited in Co₂Ti_0.5Mn_0.5Al annealed at 673 K. The MTJ using a Co₂Ti_0.5Mn_0.5Al electrode with B2 structure exhibited tunnel magnetoresistance(TMR) ratio of 37% at room temperature and 60% at 5 K. The TMR ratio was larger than that of MTJ using a Co₂Ti_0.5Mn_0.5Al electrode with L2₁ structure in this study.