PHYSICA C, cilt.235, ss.879-880, 1994 (SCI-Expanded)
Y3Ba4Cu7Ox and its eleven nearby compositions are prepared. The endothermic peaks around 950 degrees C are structured for some compositions. Most of the samples which are heat treated according to their own DTA/TGA results showed anomalous resistive transitions between 125 K and 260 K. XRD, SEM-EDAX and FTIR investigations reveal that the samples are multiphase. At least one of the IR absorption bands at 401, 405, 489 and 543 cm(-1) were observed in the spectra of the samples showing anomalous resistive transitions.