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Structural study of Cu$_{2-x}$Se alloys produced by mechanical alloying

K. D. Machado·J. C. de Lima·T. A. Grandi·A. A. M. Gasperini·C. E. Maurmann·S. M. Souza·C. E. M. Campos·A. F. Pimenta
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Abstract

The crystalline structures of superionic high temperature copper selenides Cu$_{2-x}$Se ($0 \le x \le 0.25$) produced by Mechanical Alloying were investigated using X-ray diffraction (XRD) technique. The measured XRD patterns showed the presence of the peaks corresponding to the crystalline superionic high temperature $α$-Cu$_2$Se phase in the as-milled sample, and its structural data were determined by means of a Rietveld refinement procedure. After a heat treatment in argon at 200$^\circ$C for 90 h, this phase transforms to the superionic high temperature $α$-Cu$_{1.8}$Se phase, whose structural data where also determined through the Rietveld refinement. In this phase, a very low occupation of the trigonal 32(f) sites ($\sim 3$%) by Cu ions is found. In order to explain the evolution of the phases in the samples, two possible mechanisms are suggested: the high mobility of Cu ions in superionic phases and the intense diffusive processes in the interfacial component of samples produced by Mechanical Alloying.

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K. D. Machado, J. C. de Lima, T. A. Grandi, A. A. M. Gasperini, C. E. Maurmann, S. M. Souza, C. E. M. Campos, A. F. Pimenta. 2004-01-31. Structural study of Cu$_{2-x}$Se alloys produced by mechanical alloying. https://doi.org/10.1016/j.ssc.2005.09.006

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