講演情報
[15p-P07-51]First-principles calculations of tunnel magnetoresistance effect in lattice-matched magnetic tunnel junctions
〇(M2)Koki Horigane1, Yuto Shibata1, Mizuki Matsuzaka1, Hideo Kaiju1,2 (1.Keio Univ., 2.CSRN, Keio Univ.)
キーワード：
tunnel magnetoressitance (TMR)、magnetic tunnel junction (MTJ)、density functional theory (DFT)
We investigate the tunneling magnetoresistance (TMR) effect in lattice-matched Fe-based and FeCo-based magnetic tunnel junctions (MTJs) with MgO, SrTiO3, and InP barriers using first-principles calculations. As a result, we obtain small TMR ratios of 229%, 324%, 100%, and 426% in Fe/SrTiO3/Fe, FeCo/SrTiO3/FeCo, Fe/InP/Fe, and FeCo/InP/FeCo MTJs, in contrast to large TMR ratios of 8920% and 6420% in Fe/MgO/Fe and FeCo/MgO/FeCo MTJs, respectively. Furthermore, we find the suppression of Δ1 band conduction of majority spins as well as the enhancement of conduction through other bands leads to the decrease of TMR ratio in SrTiO3-based and InP-based MTJs, whereas the robust Δ1 band conduction of majority spins is crucial for achieving large TMR ratios in MgO-based MTJs.