Low Temperature Physics: 37, 210 (2011); https://doi.org/10.1063/1.3573664 (10 pages)
Electronic structure of chromium-doped lead telluride-based diluted magnetic semiconductors
E.P. Skipetrov, N.A. Pichugin
The Moscow State University М.В. Lomonosov , Moscow, 119992, Russia
E.I. Slyn'ko, and V.E. Slyn'ko
Институт проблем материаловедения им. И.Н. Францевича НАН Украины ул. Вильде, 5, г. Черновцы, 58001, Украина
Received September 24, 2010
The crystal structure, composition, galvanomagnetic and oscillatory properties of the Pb1–x–ySnxCryTe (x = 0, 0.05–0.30, y ≤ 0.01) alloys have been investigated with varying matrix composition and chromium impurity concentration. It is shown that the chromium impurity atoms dissolve in the crystal lattice at least up to 1 mol.%. The following increase of the chromium concentration leads to the appearance of microscopic regions enriched with chromium and inclusions of Cr–Te compounds. A decrease of the hole concentration, a p–n-conversion of the conductivity type and a pinning of the Fermi level by the chromium resonant level are observed with increasing chromium content. Initial rates of changes in the free carrier concentration on doping are determined. The dependences of electron concentration and Fermi level on tin content are calculated by the two-band Kane dispersion relation. A diagram of electronic structure rearrangement for the chromium-doped alloys with varying the matrix composition is proposed.
PACS: 71.20.Nr Semiconductor compounds;
Key words: chromium impurity, galvanomagnetic effects, Shubnikov-de Haas oscillations, deep chromium level, electronic structure.