Gd doping effect in p-type Bi2Te3 single crystals

Abstract

It is generally accepted that Bi2Te3 prepared from stoichiometric melts has p-type charge carriers generated from BiTe-type antisite defects, while Bi2Te3 grown under Te-rich condition becomes n-type due to another type of TeBi antisite defects. We report the magnetic and transport properties of GdxBi2-xTe3 prepared from stoichiometric melts, where p-type charge carriers are dominant. The physical properties of all the samples have no significant changes with varying the nominal Gd composition up to x = 0.2. Compared with n-type GdxBi2-xTe3 samples grown under Te-rich condition, we find low solubility for all the samples and no clear signature of antiferromagnetic order. These results suggest that the Gd doping rate in GdxBi2-xTe3 is governed by the type of antisite defects and charge carriers, so that the antiferromagnetic ordering is not eventually introduced.