date:MV LOMONOSOV STATE UNIV,DEPT PHYS,MOSCOW 119899,USSR
Bi-2222 phases were prepared by solid state reactions and were studied using X-ray diffraction, chemical and EDS-analysis. Compounds with composition Bi2Sr2R1.33Ce0.67Cu2O10 + delta were obtained for R = Pr, Nd, Sm-Er. The phases Bi2Sr2R2Cu2O10 + delta with similar structure but without Ce were prepared for R = Pr, Sm-Dy. For Bi2Sr2Eu2-xCu2O10 + delta the solubility limit was determined and the effect of treatment under different oxygen pressures was investigated. Weak diamagnetic signals (< 3%) were detected for some of these samples.