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

Mohd Ambri Mohamed, Pham Tien Lam, K. W. Bae, N. Otsuka

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Magnetic properties resulting from localized spins associated with antisite arsenic ions As Ga + 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 As Ga 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 As Ga + 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 As Ga defect with a doped Be atom.

Original languageEnglish
Article number123716
JournalJournal of Applied Physics
Volume110
Issue number12
DOIs
Publication statusPublished - 15 Dec 2011
Externally publishedYes

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magnetization
defects
electronics
paramagnetism
electron states
metastable state
cooling
photoexcitation
arsenic
temperature measurement
ions
magnetic properties
temperature dependence
heating
atoms

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Cooperative transition of electronic states of antisite As defects in Be-doped low-temperature-grown GaAs layers. / Mohamed, Mohd Ambri; Tien Lam, Pham; Bae, K. W.; Otsuka, N.

In: Journal of Applied Physics, Vol. 110, No. 12, 123716, 15.12.2011.

Research output: Contribution to journalArticle

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