[17p-P10-1~93] 10 Spintronics and Magnetics（Poster）

▲ [17p-P10-55] Fabrication of Fe₃O₄ magnetic tunnel junctions with Mg_xAl_1-xO_y barrier layer

Yuta Yamamoto¹, Takashi Yanase², Shimada Toshihiro², 〇Taro Nagahama² (1.Hokkaido Univ., 2.Hokkaido Univ.*)

Keywords:spintronics, Fe3O4, spinel

The Fe3O4 has been expected to be half metal, which have 100% spin polarization, from the ab initio calculations[1]. Many research groups investigated the magnetic tunnel junctions (MTJs) with Fe3O4 electrodes to obtain very high TMR, however, the reported values of TMR ratio were not so high; about 20%. Although the reason has not been clear, it could be attributed to the interface between Fe3O4 and tunnel barrier. So far, the MgO and amorphous AlOx were employed as tunnel barrier due to easy to fabricate the junctions. Since Fe3O4 has spinel structure, the difference of the crystal structure could disturb the spin transport in the MTJs. Recently, Sukegawa et al. developed the MTJs with MgAl2O4 tunnel barrier layers[2], which has spinel structure. In this study, we fabricated the Fe3O4-MTJ with MgxAl1-xOy tunnel barrier and investigated the crystal structure and the magneto-transport characteristics.