Effect of impurities on polytypism and phase transformation of gel-grown PbI2single crystals
Year: 2002
Type: conference-abstract
Abstract: Three different kinds of impurities (Ag, Zn, and Br )have been separately incorporated into PbI2 crystals during their growth from gel and the polytypism of the crystals studied by X-ray diffraction. Subsequently, phase transformation of the as-grown crystals upon heating have also been studied in each case. Higher polytypes have been found to form only in the Ag-doped crystals. The Zn-doped crystals are mostly disordered 2H types, coupled with the presence of polytype 4H in some cases. The Br-doped crystals are all heavily disordered 2H types. The phase transformations resulting from heat treatment of the crystals are also different in the three cases. An optical microscpic study of the growth features on the basal surfaces of the crystals has been made. Significant differences in the nature if the growth features have also been noticed. The undoped crystals have been found to display single growth spirals, whereas the doped crystals usually display two or more spirals. Besides several different kinds of unusual growth features have been observed on the Zn-doped crystals.
Authors: M. Soudmand, S. Habibi
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2004201855