Study of the Gd Impurity Influence on the Defect Structure of Pb1-xSnxTe Crystals by Means of119Sn M�ssbauer Spectroscopy

Abstract

Subject classification: 71.55.Eq; 76.80.+y; S8.13 Pb 1--x Sn x Te:Gd solid solutions grown from the melt by the Bridgman method and doped during growth with Gd have been investigated by means of 119 Sn Mö ssbauer spectroscopy. It was found that the doping had a considerable influence on the Mö ssbauer spectrum linewidth G. The observed changes in G were explained by changes in the local surrounding of Sn nuclei and by electric field gradient rise caused by Te vacancies. It was concluded that Gd doping during the growth of the investigated solid solution crystals caused a decrease in the concentration of Te vacancies.

Pecularities of EPR spectra of the Gd impurity in the Sn-Rich Pb1−x Sn x Te(Gd) solid solutions

“…In the present work, we study the behavior of the Gd impurity ions in the crystals of Pbl_xSnxTe solid solution, asa follow-up of the systematic investigations of the influence of this dopant on the physical properties of the IV-VI semiconductors [4][5][6][7][8]. Behavior of the Gd impurity in the investigated materials is nontrivial in many aspects, e.g., it enables one to control efficiently the structural, optical, and electrophysical parameters of lead and tin tellurides.…”

“…According to the alternative model, the existence of the Gd 3 § charge state is not indispensable for the Gd donor action [5][6][7]. At the same time, the presence of such charge state has been confirmed by electron paramagnetic resonance (EPR) studies in Gd-doped PbTe [7,8,11] and SnTe [12] crystals. Its appearance, however, depends on vafious factors, e.g., the conductivity type of the doped crystals in particular [6], whereas the Gd 3+ ion concentration is always lower (by orders of magnitude) than the total Gd concentration [6,7].…”