[5a-C18-1~12] 10.1 Emerging materials in spintronics and magnetics (including fabrication and charactrization methodologies)

▼ [5a-C18-9] Fabrication of Fe_1-xSn_x epitaxial films on MgO(001) substrates

〇Yuki Goto¹, Masato Araki¹, Takashi Yanase², Toshihiro Shimada², Taro Nagahama² (1.Hokkaido Univ., 2.Hokkaido Univ..)

Keywords:spintronics, magnetic alloy

Since Magnetic tunnel junctions (MTJs) are the most important part in the spintronics, the researchers are tackling on the development of them extensively. Although, the Fe/MgO/Fe junctions are mainstream in the spintronics due to large TMR effect, there is lattice mismatch of 4% between Fe and MgO. Such mismatch generates the interface defects that could be the source of the spin-flip scatterings, which are responsible for decrease of the TMR at high bias voltage. To control the lattice constant, alloying Fe with other element is one of the solutions. For example, Fe₃Si is the intermetallic compound with D0₃ structure based on bcc, however, the lattice constant is smaller than Fe. In this study, Fe_1-xSn_x was examined as a spintronics material because Sn is the material in group 4 as same as Si and the atomic radius is larger than Si. As a result, we succeeded to alloying Sn with Fe with maintaining body center cubic (bcc) structure. In particular, B2 type Fe₃Sn which is metastable phase was realized by epitaxial growth, although the stable structure of Fe3Sn is D0₁₉, hexagonal structure. In addition, the lattice constant increased with increasing of Sn composition.