Effect of preparation conditions on the orientation of Y-Ba-Cu oxide powders during X-ray diffractometry

Abstract

X-ray powder diffraction intensities of (00 l) reflections of the orthorhombic 1-2-3 phase are found to depend strongly on the preparation conditions, particularly the calcination temperature of the raw materials. Calcination temperatures above around 925°C cause formation of relatively large crystals of the 1-2-3 phase which retain their morphology even after subsequent sintering. Grinding of these coarse grained specimens leads to relatively more flaky particles due to cleavage fracture along (00 l) planes resulting in a strong orientation effect particularly during X-ray powder diffractometry.