Semi-Quantitative Analysis for Phases in the Y sub 2 O sub 3 --BaO--CuO System

Semi-quantitative analysis of multi-phase crystalline samples is possible by X-ray powder diffraction when the reference intensity ratio I:I sub c is known for each phase in the sample. The Y sub 2 O sub 3 --BaO--CuO system contains a number of phases for which I:I sub c is not known and which may form during efforts to synthesize YBa sub 2 Cu sub 3 O sub 7 . The I:I sub c value for a number of these phases has been determined. I:I sub c is the ratio of the intensity of the most intense powder diffraction line of a phase to the most intense line of corundum, i.e. the 113 reflection (d = 2.085 A) which occurs at 2 theta = 43.36 deg when Cu K alpha radiation is used. X-ray diffraction reference intensity ratios have been determined for a number of phases that may form during synthesis of the superconductor YBa sub 2 Cu sub 3 O sub 7-- delta . These ratios enable one to perform semi-quantitative analyses of samples containing these phases. The method has been tested for these phases and is accurate to plus /minus 2 wt.%. 2 ref.--AA