Thermal properties of the magnetic RuSr2GdCu2O8 superconductor

A thermal study was performed on the RuSr2GdCu2O8 (Ru-1212) magnetic superconductor phase to investigate the effect of the annealingtreatments in flowing O2 on the stability limit of the phase and on its structural, magnetic and transport properties. DTA-TG measurements were utilized to determine the decomposition process and the dependence of the decomposition temperatureon the annealing atmosphere. The decomposition of the Ru-1212 phase was found sensitive to the oxygen partial pressure and increases with PO2 and the annealingtime. The annealing treatments exert a depressing effect on the strength of the magnetic interaction, an enhancement on the superconductiveproperties and the vanishing of the magnetostriction.A decomposition reaction of Ru-1212 phase was proposed and discussed.