Cooperative transition of electronic states of antisite As defects in Be-doped low-temperature-grown GaAs layers

Mohamed, Mohd Ambri and Tien Lam, Pham and Bae, K. W. and Otsuka, Nobuo (2011) Cooperative transition of electronic states of antisite As defects in Be-doped low-temperature-grown GaAs layers. Journal of Applied Physics, 110 (12). ISSN 0021-8979

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Abstract

Magnetic properties resulting from localized spins associated with antisite arsenic ions AsGa+ in Be-doped low-temperature-grown GaAs (LT-GaAs) layers were studied by measuring the magnetization of lift-off samples. With fast cooling, the magnetization of samples at 1.8 K becomes significantly lower than that expected from Curie-type paramagnetism in the range of the applied field to 7 T, and a transition from low magnetization to the magnetization of paramagnetism occurs upon the heating of samples to 4.5 K. With slow cooling, on the other hand, samples have a paramagnetic temperature dependence throughout the measurement-temperature range. The magnetization was found to decrease monotonically when a sample was kept at a fixed low temperature. These observations are explained by the cooperative transition of electron states of AsGa defects, which is closely related to the normal-metastable state transition of EL2 defects in semi-insulating GaAs. The results of the magnetization measurements in the present study suggest that AsGa+ ions are spontaneously displaced at low temperature without photoexcitation in Be-doped LT-GaAs. The similarity of the transition observed in this system to the normal-metastable state transition of the EL2 defect was also suggested by first-principle calculations of the electron state of an AsGa defect with a doped Be atom

Item Type:	Article (Journal)
Additional Information:	6933/29874
Subjects:	Q Science > QC Physics Q Science > QD Chemistry T Technology > TK Electrical engineering. Electronics Nuclear engineering > TK7800 Electronics. Computer engineering. Computer hardware. Photoelectronic devices > TK7885 Computer engineering
Kulliyyahs/Centres/Divisions/Institutes (Can select more than one option. Press CONTROL button):	International Institute of Islamic Thought and Civilization (ISTAC)
Depositing User:	Dr Mohd Ambri Mohamed
Date Deposited:	25 Jul 2013 15:02
Last Modified:	09 Sep 2015 11:05
URI:	http://irep.iium.edu.my/id/eprint/29874

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