Characterisation of the LaGdO3 by X-Ray Powder Diffraction and Raman Spectroscopy

Abstract

LaGdO3 is prepared via a reverse-strike coprecipitation method and sintered at temperatures of 1350-1450 degrees C for 6 h. Raman spectroscopy of the sintered materials revealed profiles similar to that observed for pure B-type Gd2O3. Low temperature (-196 degrees C) Raman spectra showed a total of 18 bands of a possible 21 allowed modes predicted for the monoclinic B-type mixed rare earth oxide with C2/m space group. These bands were assigned to modes in comparison to the band assignments for Gd2O3 as follows; 71 (B-g), 82 (A(g)), 98 (B-g), 109 (A(g)), 124 (A(g)) 158 (A(g)), 182 (A(g)) 219 (A(g)), 242 (A(g)) 279 (A(g)), 315 (B-g). 366 (A(g)) 390 (B-g), 419 [B-g + (A(g)?)], 436 (A(g)), 458 (A(g)), 560 (A(g)) and 575 (A(g)) cm(-1). Powder X-ray diffraction patterns revealed a monoclinic pattern for materials sintered at all three temperatures; 1350, 1400 and 1450 degrees C. (C) 1998 Elsevier Science Ltd. All rights reserved.