THE Y2BACUO5 OXIDE AS GREEN PIGMENT IN CERAMICS

Fine particles of green yttrium-barium-copper-oxide pigments Y2BaCuO5 have been prepared using two different synthesis methods. The process of combustion of mixed nitrates and urea needs a maximal temperature o f 900 degrees C and provides samples formed by aggregates of homogeneo us small particles with a size of about 0.3 mu m. However, the ceramic method requires 1050 degrees C as synthesis temperature, and yields r ather higher particle sizes. Even after grinding, these samples are fo rmed by heterogeneous particles with mean sizes of about 3 mu m. Diffu se reflectance spectra reveal that the samples obtained using the form er method present a higher brilliancy, so they have been selected to b e tested as green pigment in ceramics with good results. (C) 1998 Else vier Science S.A.