X-ray spectral microanalysis of the phase composition of high temperature superconductor bismuth–lead–strontium–calcium–copper–oxygen ceramics using chemometric approaches

Abstract

The work described in this paper deals with the investigation of the phase composition of high temperature (T_c) superconductor (HTSC) ceramic samples with the help of cluster and principal component analyses (CA and PCA) of the electron microprobe data. The peculiarities of the joint application of CA and PCA are shown. The phase composition of eight specially fabricated Bi—Pb—Sr—Cu—O samples is determined. The results of the investigation are compared with those obtained by X-ray diffraction (XRD), differential thermal (DTA) and differential dissolution (DDA) analyses. The correlations between the Bi, Sr and Cu contents are revealed and their nature is discussed. Finally, it is concluded that the valence of Bi is +2.