Influence of calcination temperature on lattice parameters and particle size of R{sub 2}CuO{sub 4} compounds (R = Gd,Nd) prepared by a sol-gel method
- Univ. of Santiago de Compostela (Spain); and others
Cuprates R{sub 2}CuO{sub 4} (R = Gd, Nd) were prepared by a sol-gel method that allowed control of the mean particle size by calcining at different temperatures. The samples were characterized using X-ray diffractometry (XRD) and transmission electron microscopy. The results show that the structure of these cuprates is sensitive to the preparation method, particularly the calcination temperature, T{sub cal}. The refined lattice parameters {alpha} and c, and unit-cell volume V, obtained from the XRD data by the Rietveld method, are found to decrease with increasing T{sub cal}, while their mean particle size increased. Between 650 and 950{degrees}C, the relative decreases in the lattice parameters were found to be larger for Gd{sub 2}CuO{sub 4} than for Nd{sub 2}CuO{sub 4}(e.g., 0.07 and 0.03%, respectively, for c). Furthermore, samples prepared by a standard solid state reaction had smaller lattice parameters than the samples prepared by the sol-gel method calcined at lower T{sub cal}, while the values for the sol-gel samples calcined at higher T{sub cal} approximate those for the solid state reaction samples.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 263725
- Journal Information:
- Journal of Solid State Chemistry, Vol. 122, Issue 1; Other Information: PBD: 15 Feb 1996
- Country of Publication:
- United States
- Language:
- English
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