Microstructure and phase composition of hypoeutectic Te–Bi alloy as evaporation source for photoelectric cathode

• Published in: International journal of minerals, metallurgy and materials Vol. 25; no. 5; pp. 584 - 590
• Main Authors: Wang, Bao-guang, Yang, Wen-hui, Gao, Hong-ye, Tian, Wen-huai
• Format: Journal Article
• Language: English
• Published: Beijing University of Science and Technology Beijing 01.05.2018; Springer Nature B.V; School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China%Faculty of Engineering Sciences, Kyushu University, Fukuoka 8190395, Japan
• Subjects: Bismuth base alloys; Bismuth tellurides; Ceramics; Characterization and Evaluation of Materials; Chemical composition; Chemistry and Materials Science; Composites; Corrosion and Coatings; Crystal structure; Crystallography; Electron backscatter diffraction; Electron microscopy; Eutectics; Evaporation; Glass; Light microscopy; Materials Science; Metallic Materials; Microscopy; Microstructure; Natural Materials; Optical microscopy; Phase composition; Photocathodes; Photoelectricity; Solidification; Surfaces and Interfaces; Tellurium; Thin Films; Tribology; X-ray diffraction; orientation; microstructure; Te–Bi alloy; misfit; Te-Bi alloy
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-018-1605-8

A hypoeutectic 60Te–40Bi alloy in mass percent was designed as a tellurium atom evaporation source instead of pure tellurium for an ultraviolet detection photocathode. The alloy was prepared by slow solidification at about 10 −2 K·s −1 . The microstructure, crystal structure, chemical composition, and crystallographic orientation of each phase in the as-prepared alloy were investigated by optical microscopy, scanning electron microscopy, X-ray diffraction, electron backscatter diffraction, and transmission electron microscopy. The experimental results suggest that the as-prepared 60Te–40Bi alloy consists of primary Bi 2 Te 3 and eutectic Bi 2 Te 3 /Te phases. The primary Bi2Te3 phase has the characteristics of faceted growth. The eutectic Bi2Te3 phase is encased by the eutectic Te phase in the eutectic structure. The purity of the eutectic Te phase reaches 100wt% owing to the slow solidification. In the eutectic phases, the crystallographic orientation relationship between Bi 2 Te 3 and Te is confirmed as [ 0001 ] B i 2 T e 3 / / [ 1 2 ¯ 1 3 ¯ ] T e and the direction of Te phase parallel to [ 11 2 ¯ 0 ] B i 2 T e 3 is deviated by 18° from Te N ( 2 1 ¯ 1 ¯ 1 ) T e .