Influence of Temperature on the Order-Disorder Transition in Gd sub(2) Zr sub(2) O sub(7)

• Published in: Key Engineering Materials Vol. 697; pp. 386 - 389
• Main Authors: Shi, Jing Lin, Qu, Zhi Xue, Wang, Qun
• Format: Journal Article
• Language: English
• Published: 01.07.2016
• Subjects: Coprecipitation; Diffraction; Diffraction patterns; Fluorite; Order disorder; Pyrochlores; Spectra; X-rays
• ISBN: 9783035710656; 3035710651
• ISSN: 1013-9826; 1662-9795
• DOI: 10.4028/www.scientific.net/KEM.697.386

Chemical co-precipitation method was used to prepare Gd sub(2) Zr sub(2) O sub(7) powders. The powders were then heated in air at 1500[degrees]C, 1510[degrees]C, 1525[degrees]C, 1530[degrees]C, 1550[degrees]C, 1575[degrees]C, 1600[degrees]C for 5 h, and 1575[degrees]C, 1600[degrees]C for 10 h, respectively. The samples after heat treatment were characterized by X-ray diffraction and Raman spectroscopy. X-ray diffraction patterns reveal that order-disorder transition of Gd sub(2) Zr sub(2) O sub(7) occurs between 1550[degrees]C and 1575[degrees]C. Prior to the transition, the relative intensity of peaks corresponding to the super-lattice of pyrochlores increases with the increasing temperature. On the other hand, Raman spectra give an inconsistent result from the X-ray diffraction data. No appreciable difference can be observed for all the samples though with peaks broadening as temperature increases. The spectra of the samples indicated as fluorite structure in X-ray diffraction patterns appear with six resolvable peaks which is quite different from the spectrum of ideal fluorite structure.