15:00 〜 15:15
▲ [12p-M101-8] Magnetic anisotropy switching in heavily-Fe-doped high-Curie-temperature ferromagnetic semiconductor (Ga0.7,Fe0.3)Sb with a critical thickness
キーワード：Ferromagnetic Semiconductor, Ferromagnetic Resonance, Magnetic Anisotropy Constants
Fe-doped FMS (Ga,Fe)Sb, which shows a high Curie temperatureTC (> 300 K)1 is more promising for room temperature device application compare to GaMnAs whose TC is low (<200K)2. Previously, we have investigated strain effect on magnetic anisotropy (MA) of Ga0.8Fe0.2Sb and found that inplane magnetic anisotropy (IMA) is dominant due to large shape anisotropy3.
In this work, to control the MA of (Ga,Fe)Sb, we have investigated the thickness (d) dependence of the MA of (Ga0.7,Fe0.3)Sb (d = 20, 30, 40, and 55 nm) grown by low-temperature molecular-beam epitaxy (LT-MBE) on AlSb using semi-insulating GaAs(001) substrates. We estimated the MA constants by measuring ferromagnetic resonance (FMR) and magnetization using a superconducting quantum interference device (SQUID) at room temperature. We estimated the effective MA constants (Keff) of all samples. We show that the negative sign of Keff represents the IMA, while the positive sign corresponds to the perpendicular magnetic anisotropy (PMA). To analyze d dependence of MA, we separated the Keff into bulk and interface contributions where interface contribution is negative sign which causes IMA whereas bulk contribution is positive sign which causes PMA.
This work was partly supported by Grants-in-Aid for Scientific Research (No. 26249039, No. 17H04922, No. 16H02095, and 18H03860), CREST Program (JPMJCR1777) of JST, Spintronics Research Network of Japan (Spin-RNJ), and the Murata Science Foundation.
References:
[1] N. T. Tu et.al., Phys. Rev. B 92, 144403 (2015).
[2] Seul-Ki Bac et. al., Appl. Phys. Express 8, 033201 (2015).
[3] S. Goel, L. D. Anh, S. Ohya, and M. Tanaka, Phys. Rev. B (2019), in press.
In this work, to control the MA of (Ga,Fe)Sb, we have investigated the thickness (d) dependence of the MA of (Ga0.7,Fe0.3)Sb (d = 20, 30, 40, and 55 nm) grown by low-temperature molecular-beam epitaxy (LT-MBE) on AlSb using semi-insulating GaAs(001) substrates. We estimated the MA constants by measuring ferromagnetic resonance (FMR) and magnetization using a superconducting quantum interference device (SQUID) at room temperature. We estimated the effective MA constants (Keff) of all samples. We show that the negative sign of Keff represents the IMA, while the positive sign corresponds to the perpendicular magnetic anisotropy (PMA). To analyze d dependence of MA, we separated the Keff into bulk and interface contributions where interface contribution is negative sign which causes IMA whereas bulk contribution is positive sign which causes PMA.
This work was partly supported by Grants-in-Aid for Scientific Research (No. 26249039, No. 17H04922, No. 16H02095, and 18H03860), CREST Program (JPMJCR1777) of JST, Spintronics Research Network of Japan (Spin-RNJ), and the Murata Science Foundation.
References:
[1] N. T. Tu et.al., Phys. Rev. B 92, 144403 (2015).
[2] Seul-Ki Bac et. al., Appl. Phys. Express 8, 033201 (2015).
[3] S. Goel, L. D. Anh, S. Ohya, and M. Tanaka, Phys. Rev. B (2019), in press.