2020年第67回応用物理学会春季学術講演会

講演情報

一般セッション(口頭講演)

10 スピントロニクス・マグネティクス » 10.4 半導体スピントロニクス・超伝導・強相関

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

2020年3月12日(木) 13:15 〜 17:45 A501 (6-501)

ファム ナムハイ(東工大)、高村 陽太(東工大)、黒田 眞司(筑波大)

13:45 〜 14:00

[12p-A501-3] Carrier type switching in quaternary alloy ferromagnetic semiconductor (In,Ga,Fe)Sb
by controlling the composition of In and Ga

Tomoki Hotta1、Kengo Takase1、Kosuke Takiguchi1、Suriharsha Karumuri1、Anh Le Duc1,2、Masaaki Tanaka1,3 (1.Univ. of Tokyo、2.IEI, Univ. of Tokyo、3.CSRN)

キーワード:ferromagnetic semiconductor, high Curie temperature, spintronics

Ferromagnetic semiconductors (FMSs) are promising materials for low-power spin-based devices because they show both the properties of ferromagnets and semiconductors. Recently, we have successfully grown both p-type and n-type Fe-doped III-V FMSs with high Curie temperature (TC); p-type (Ga,Fe)Sb with TC = 400 K and n-type (In,Fe)Sb with TC = 385 K by low-temperature molecular-beam epitaxy (LT-MBE). With alloying p-type (Ga,Fe)Sb and n-type (In,Fe)Sb, we may be able to switch the carrier type with only a slight change of the lattice constant and band structure while maintaining high TC, which will be useful for understanding the origin of the carrier type and ferromagnetism in the Fe-doped FMSs. In this work, we have grown both p-type and n-type (In1-x-y,Gax,Fey)Sb thin films with room-temperature ferromagnetism. We grew heterostructures consisting of (from top to bottom) InSb (2 nm) / (In1-x-y,Gax,Fey)Sb (15 nm, x = 2, 4, 6, 8, 10 %, y = 16 %) / AlSb (100 nm) / AlAs (6 nm) / GaAs (100 nm) on a semi-insulating GaAs(001) substrate by LT-MBE. From the linear slope of the RHall – magnetic field (H) at high H (> 10000 Oe), the carrier type of (In1-x-y,Gax,Fey)Sb is found to be switched from p-type to n-type by decreasing x from 10 % to 6 %. This trend is consistent with the previous result; (In,Fe)Sb is n-type and (Ga,Fe)Sb is p-type. The carrier type of (In1-x-y,Gax,Fey)Sb can be changed between p-type and n-type with a slight change of the lattice constant and band structure.