MOSSBAUER, CRYSTAL-STRUCTURE, MAGNETIC, AND RAMAN STUDIES OF THE (Y,CE)2SR2CUFEO8 COMPOUND ISOMORPHIC TO SUPERCONDUCTORS WITH THE T-ASTERISK STRUCTURE

The crystal structure, the magnetic and transport properties, and the lattice vibrations of the (Y,Ce)2Sr2CuFeO8 compound were studied by Ri etveld refinement, Mossbauer spectroscopy, dc magnetic susceptibility, electrical-resistivity measurements, and Raman spectroscopy. The Riet veld-refinement results and Raman spectra show that the space group wh ich describes the structure is P4mm. Mossbauer spectra can be fitted w ith one component with hyperfine parameters which correspond to Fe+3 i n a high-spin state coordinated by five oxygen atoms arranged in a squ are pyramid. Most of the observed phonon lines can be assigned to defi nite atomic vibrations. Magnetic measurements show an antiferromagneti c transition at 30 K. Fitting of dc-susceptibility data in the paramag netic region gives an effective magnetic moment of (3.6 +/- 0.1)mu(B) per ion. The resistivity data show insulating behavior.