Open AccessStructural and chemical analysis of grain boundaries and tellurium precipitates in commercial Cd{sub 1{minus}x}Zn{sub x}Te
Author(s) -
J. R. Heffelfinger,
Douglas L. Medlin,
R. B. James
Publication year - 1998
Language(s) - English
Resource type - Reports
DOI - 10.2172/638238
Subject(s) - tellurium , grain boundary , transmission electron microscopy , crystallography , materials science , analytical chemistry (journal) , x ray crystallography , selected area diffraction , scanning electron microscope , electron diffraction , chemistry , diffraction , microstructure , metallurgy , optics , nanotechnology , physics , chromatography , composite material
The structure and chemistry of grain boundaries in commercial Cd{sub 1{minus}x}Zn{sub x}Te, prepared by the high-pressure Bridgman technique, have been analyzed using transmission electron microscopy, scanning electron microscopy, infrared-light microscopy and visible-light microscopy. These analyses show that the grain boundaries inside the Cd{sub 1{minus}x}Zn{sub x}Te materials are decorated with tellurium precipitates. Analysis of a tellurium precipitate at a grain boundary by transmission electron microscopy and selected-area electron diffraction found the precipitate to consist of a single, saucer-shaped grain. Electron diffraction from the precipitate was consistent with the trigonal phase of tellurium (space group P3{sub 1}21), which is the equilibrium phase at room temperature and atmospheric pressure. This precipitate was found to be aligned with one of the adjacent CZT grains such that the tellurium (0{bar 1}11) planes were nearly parallel to the CZT (111) planes. High-resolution transmission electron microscopy of the Te/Cd{sub 1{minus}x}Zn{sub x}Te interface showed no tertiary phase at the interface. The structures of the grain boundaries and the Te/Cd{sub 1{minus}x}Zn{sub x}Te interface are discussed and related to their possible implications on Cd{sub 1{minus}x}Zn{sub x}Te gamma-ray detector performance