Transport coefficients oftitanium-doped Sb2Te3 crystals


P. Svanda1, P.Lostak1, C. Drasar1, W. Chen2, J.S. Dyck2, C. Uher2


1 Faculty of ChemicalTechnology, University of Pardubice, Cs. Legii Square 565,

532 10 Pardubice, Czech Republic

2 Department of Physics,University of Michigan, Ann Arbor, MI 48109-1120, USA


Titanium-dopedsingle crystals (cTi = 0 to 2x1020 atoms cm-3)were prepared from the elements Sb, Ti, and Te of 5N purity by a modifiedBridgman method. The obtained crystals were characterized by measurements ofthe temperature dependence of the electrical resistivity, Hall coefficient,Seebeck coefficient and thermal conductivity in the temperature range of 5-300K. It was observed that with an increasing Ti content in the samples theelectrical resistance, the Hall coefficient and the Seebeck coefficientincrease. This means that the incorporation ofTi atoms into the Sb2Te3 crystal structure results in adecrease in the concentration of holes in the doped crystals. For theexplanation of the observed effect a model of defects in the crystals isproposed.