Sb2Te3 Single Crystals Doped with Chromium Atoms

Chromium‐doped Sb2Te3 single crystals were prepared from elements of semiconductor purity using a modified Bridgman method. The samples of these crystals were characterized by means of X‐ray diffraction analysis, measurements of the reflectivity in the plasma resonance frequency range ωp, of the Hall constant RH and electrical conductivity σ. It was found that the incorporation of Cr atoms into the Sb2Te3 crystal lattice reduces the volume of the unit cell, whereas the values of ωp and RH (i.e. the concentration of holes) remain unaltered and the values of σ decrease with increasing chromium content. This effect is qualitatively explained by an interaction of incorporated Cr atoms with antisite defects of Sb2Te3 crystal lattice. The In (RHσ) vs. In T dependences show that the dominant mechanism of scattering of free charge carriers in the studied crystals is the scattering by acoustic phonons; the presence of chromium atoms increases the scattering rate by ionized impurities.