Preparative and Mössbauer studies of Bi2Sr2Ca n-1Cu n O y compounds withn=2 or 3

The influence of sintering temperatures and nominal starting compositions on the phase contents of polycrystalline Bi2Sr2Ca n-1Cu n O4+2n samples are reported. After every sintering the samples were characterized with X-ray diffraction and magnetic AC susceptibility measurements. For Mossbauer studies, in each case also a corresponding specimen containing57Fe was synthetized. The identification of various superconducting Bi2Sr2Ca n-1Cu n O4+2n phases on the basis of Mossbauer spectra consisting usually of three quadrupole doublets is discussed.