Clusters and the Nature of Superconductivity in Ltmbe-GaAs

Autor: M. P. Yakubenya, V. V. Tret’yakov, S. I. Goloshchapov, D. I. Lubyshev, M. D. Vilisova, V. V. Chaldyshev, B. R. Semyagin, A. I. Veinger, V. V. Preobrazhenskii, N. A. Bert, I. V. Ivonin, A. E. Kunitsyn, S. V. Kozyrev, L. G. Lavrentieva
Rok vydání: 1993
Předmět:
Zdroj: Scopus-Elsevier
ISSN: 1946-4274
0272-9172
DOI: 10.1557/proc-325-401
Popis: The structure and properties of GaAs layers grown by molecular-beam epitaxy at low temperature (150-250 °C) have been studied. The samples were found to contain up to 1.5 at.% extra As, which formed nano-scale clusters under annealing. The dependences of the excessive As concentration and As-cluster size and density on the growth and annealing conditions were established. LT-GaAs layers were found to have high electrical resistivity, however, our investigations of microwave absorption in a weak magnetic field revealed a characteristic signal usually attributed to the superconducting phase. It has been proved that this microwave absorption is unlikely to be due to either the arsenic clusters in LT-GaAs films or indium in the substrate, as it was assumed previously. We suggest a new hypothesis that the superconducting phase in LT-GaAs is Ga nanoclusters formed on the growth surface.
Databáze: OpenAIRE
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