[12p-A501-1~16] 10.4 半導体スピントロニクス・超伝導・強相関

▼ [12p-A501-2] Epitaxial growth and characterizations of quaternary alloy ferromagnetic semiconductor (In,Ga,Fe)Sb

〇Kengo Takase¹、Tomoki Hotta¹、Kosuke Takiguchi¹、Sriharsha Karumuri¹、Anh Le Duc^1,2、Masaaki tanaka^1,3 (1.Tokyo Univ. Eng.、2.Tokyo Univ. IEI、3.Tokyo Univ. CSRN)

キーワード：ferromagnetic semiconductor, room temperature ferromagnetism

We present a new type of Fe-doped quaternary alloy FMS, (In_1-x-y,Ga_x,Fe_y)Sb, with room-temperature ferromagnetism grown by low-temperature molecular-beam epitaxy (LT-MBE). An X-ray diffraction (XRD) spectrum suggests that the (In_0.74,Ga_0.1,Fe_0.16)Sb layer maintains the zinc-blende crystal structure without any other second phases. The lattice constant of (In_0.74,Ga_0.1,Fe_0.16)Sb follows the Vegard’s law, suggesting that In and Ga atoms reside in the group-III sites. Normalized magnetic circular dichroism (MCD) spectra measured at 5 K with a magnetic field of 1 T, 0.5 T and 0.2 T applied perpendicularly to the film plane overlap on a single spectrum in the whole photon-energy range from 1.5 eV to 4.5 eV, indicating intrinsic and homogeneous ferromagnetism in the (In_0.74,Ga_0.1,Fe_0.16)Sb film. Curie temperature (T_C) of the (In_0.74,Ga_0.1,Fe_0.16)Sb film reaches 320 K. This high T_C and good crystal quality are promising for realizing more materials functionalities and device applications.