Structural study of Cu(2-x)Se alloys produced by mechanical alloying.
The crystalline structures of the superionic high-temperature copper selenides Cu(2-x)Se (0 < x < 0.25) produced using mechanical alloying were investigated using X-ray diffraction (XRD). The measured XRD patterns showed the presence of peaks corresponding to the crystalline superionic high-temperature alpha-Cu(2)Se phase in the as-milled sample, and its structural data were determined by means of a Rietveld refinement procedure. After heat treatment in argon at 473 K for 90 h, this phase transforms to the superionic high-temperature alpha-Cu(1.8)Se phase, whose structural data were also determined by Rietveld refinement. In this phase, a very low occupation of the trigonal 32(f) sites ( approximately 3%) by Cu ions is found. In order to explain the evolution of the phases in the samples, two possible mechanisms are suggested: (i). the high mobility of Cu ions in superionic phases and (ii). the important diffusive processes in the interfacial component of samples produced by mechanical alloying.
Machado
K D
KD
Depto de Física, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina 88040-900, Cx. P. 476, Brazil. kleber@fisica.ufsc.br
de Lima
J C
JC
Grandi
T A
TA
Campos
C E M
CE
Maurmann
C E
CE
Gasperini
A A M
AA
Souza
S M
SM
Pimenta
A F
AF
D000497:Alloys / Q000138:chemical synthesis / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D006358:Hot Temperature; D008968:Molecular Conformation; D033362:Powder Diffraction; D012643:Selenium / Q000737:chemistry*; D014961:X-Ray Diffraction
D000497:Alloys; D003300:Copper; D012643:Selenium