Structural study of chalcogenide glasses in the Bi5As35Se60-xTex system

Publication date: 1 November 2019Source: Journal of Non-Crystalline Solids, Volume 523Author(s): Jianhua Zheng, Lei Li, Haiwei Yin, Yang Wang, Huidan Zeng, Jie Wei, Guorong ChenAbstractThe atomic structure of chalcogenide glasses in the composition of As35Se60-xTexBi5 (x = 0, 5, 10, 15, 20) is investigated by XRD, Raman spectroscopy and HR-XPS. All results present the consistent evidences on association of Te addition with the structural evolution of glasses. XRD patterns show that the Te can be added into the As35Se60Bi5 system to substitute Se by maximum 15 mol% without causing crystallization. Raman and HR-XPS spectra demonstrate that the substitution of Te for Se is closely related to formation of locally ordered nanostructure in glass network. In low concentration, Te atoms are preferentially bonded with As rather than Bi, forming mixed [AsSe3-xTex] pyramid units. With the increasing of Te content, Te atoms tend to be bonded with Bi to form [BiSe3-xTex] units. In the case of Te incorporation over 20 mol%, the BiTe bond becomes further strengthened, inducing the precipitation of the sole thermoelectric crystals (Bi2Se3-xTex).
Source: Journal of Non Crystalline Solids - Category: Chemistry Source Type: research