MICRO-RAMAN, SEM AND X-RAY CHARACTERIZATION OF (PB0.6CU0.5)LASRCAN-1CUNOX (N=1, 2) CERAMICS

Ceramic samples of (Pb0.6Cu0.5)LaSrCan-1CunOx, (n= 1, 2) were synthesi zed in air and characterized using micro-Raman spectroscopy, scanning electron microscopy and X-ray diffraction. In the (Pb0.6Cu0.5)LaSrCuOx ceramics the following phases were identified: (Pb0.5Cu0.5)LaSrCuO5+d elta, (Sr,La)1(Pb,Cu)1O3, (Sr,Ca)14Cu24O41 and (La8-xSrx)Cu8O20-delta; in the (Pb0.6Cu0.5)LaSrCaCu2Ox ceramics: (Pb0.5Cu0.5)LaSrCaCu2O7-delt a, (Sr,Ca,La)14Cu24O41, (Sr,Ca,La)1(Pb,Cu)1O3 and Ca2PbO4. The polariz ed Raman spectra of (Pb0.5Cu0.5)LaSrCan-1CunOx (n=1, 2) are discussed accounting for the disorder in the (Pb,Cu)-O planes. A comparison of t he (Sr,Ca,La)1(Pb,Cu)1O3 pseudocubic perovskite phase with the Dou's p hase (the hexagonal Pb3Sr2Ca2Cu1Ox) suggests that the structure of the latter compound could be considered as a slightly deformed perovskite . Raman spectra of the other additional phases were also measured and discussed.