[13p-P8-1~46] 10 Spintronics and Magnetics(Poster)

[13p-P8-19] Fabrication of magnetic tunnel junctions constituted by Heusler alloys Co_2-x(Fe_0.4Mn_0.6)_1+xSi

〇Shinichi Horiuchi¹, Mikihiko Oogane¹, Yasuo Ando¹ (1.Tohoku Univ.)

Keywords:magnetic tunnel junction, Heusler alloy, tunnel magneto resistance

For the realization of high tunnel magnetoresistance (TMR) effect in ferromagnetic tunnel junction (MTJ) element, half-metal Heusler alloys are attracting most attention these days. Recently, with the intent to improve the half-metallicity of the Heusler alloy, high TMR ratio has been achieved by using a non-stoichiometric composition Co₂(Fe_αMn_β)Si_0.84. However, details such as the mechanism are not revealed. This study aimed to perform the verification. We prepared thin films and MTJs with Co_2-x(Fe_0.4Mn_0.6)_1+xSi, and evaluated crystallinity and surface-flatness. Further, TMR ratio of the MTJ element fabricated under optimum conditions, was up to 224 % at room temperature.