低抵抗強磁性トンネル接合の温度・バイアス特性  [in Japanese] Temperature and Bias Voltage Dependence of Ferromagnetic Tunneling Junctions  [in Japanese]

The bias and temperature dependences of tunneling magnetoresistance (TMR) were investigated for Fe/Al_2O_3/CoFe with a relatively small tunneling impedance (resistance times area: R×A〜1.8×10^<-9>Ωm^2). Despite a rather thinner and lower tunneling barrier, the change in conductance under a magnetic field obeys an a-bT^<3/2> dependence, suggesting the dominance of the contribution of the decrease in effective spin polarzation with temperature. In addition to a monotonic decrease in the magnitude of the TMR with increasing bias voltage, there is a slight change in the field dependence in low fields.