Статья

Effect of Be doping on the properties of GaMnAs ferromagnetic semiconductors

Sang‐Hoon LeeDepartment of Physics, Korea University, Seoul 136-701, KoreaS. J. ChungDepartment of Physics, Korea University, Seoul 136-701, KoreaI. S. ChoiDepartment of Physics, Korea University, Seoul 136-701, KoreaSh. U. YuldeshevQuantum Functional Semiconductor Research Center, Dongguk University, Seoul 100-715, KoreaHyunsik ImQuantum Functional Semiconductor Research Center, Dongguk University, Seoul 100-715, KoreaTae Won KangQuantum Functional Semiconductor Research Center, Dongguk University, Seoul 100-715, KoreaW. L. LimDepartment of Physics, University of Notre Dame, Notre Dame, Indiana 46556Yuji C. SasakiDepartment of Physics, University of Notre Dame, Notre Dame, Indiana 46556X. LiuDepartment of Physics, University of Notre Dame, Notre Dame, Indiana 46556T. WójtowiczPolish Academy of SciencesJ. K. FurdynaDepartment of Physics, University of Notre Dame, Notre Dame, Indiana 46556

2003en

ABI

Аннотация

We have studied two series of molecular beam epitaxy grown Ga1−xMnxAs epilayers with several different Be doping levels. Two Mn concentrations x were chosen for this study: 0.03 and 0.05, and these values were maintained constant in each series. These samples were characterized by using SQUID and magnetotransport measurements. A systematic increase of the Curie temperature TC was observed in SQUID measurements on the series of Ga1−xMnxAs with x=0.03. The resistivity measured at zero magnetic field shows a local maximum near the Curie temperature, reflecting the effects of critical scattering near TC. The observed increase of TC in Ga1−xMnxAs for this low range of x can be explained by the increase of the free carrier concentrations in the system arising from Be doping. However, in the series of Ga1−xMnxAs with the higher concentration of Mn (x=0.05), the measurements reveal that the TC systematically decreases with increasing Be doping level. We discuss this effect in terms of a fundamental limitation of the carrier concentration that can be thermodynamically accommodated by Ga1−xMnxAs epilayers.

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Идентификаторы

DOI: 10.1063/1.1556272

Цитирования и источники

Цитирований: 3Использованных источников: 0

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