[16a-3A-1~10] 10.4 半導体・有機・光・量子スピントロニクス

▲ [16a-3A-6] Growth and characterization of insulating ferromagnetic semiconductor (Al,Fe)Sb

〇(D)Anh Le¹, Daiki Kaneko¹, Pham Nam Hai², Masaaki Tanaka¹ (1.Tokyo Univ., 2.Tokyo Inst. of Tech.)

キーワード：spin filter,ferromagnetic semiconductor,Fe-based FMS

We investigate the crystal structure, transport and magnetic properties of Fe-doped ferromagnetic semiconductor (Al_1-x,Fe_x)Sb up to x = 14% grown by molecular beam epitaxy. All samples show p-type conduction at room temperature and insulating behavior at low temperature. Careful chracterization of the crystal structure by X-ray diffraction and scanning transmission electron microscopy shows that (Al_1-x,Fe_x)Sb samples with x ≤ 10% maintain the zinc blende crystal structure of the host material AlSb. Intrinsic ferromagnetism with a Curie temperature (T_C) of 40 K was observed for the sample with x = 10% Fe. This is the first observation of ferromagnetism in Al-V (As or Sb) semiconductors, which paves the way to realize a spin-filtering tunnel barrier that is compatible to III-V semiconductors spin devices.