SPECIFIC-HEAT OF BI2SR2CACU2O8-FIELDS UP TO 16-TESLA(X IN MAGNETIC)

High resolution specific heat measurements of Bi2Sr2CaCu2O8+x supercon ductors in magnetic fields up to 16 Tesla are presented. In a polycrys talline sample the magnetic field leads to a drastic suppression and a pronounced broadening of the anomaly at T-c. In contrast, our measure ments on a high quality single crystal for fields parallel to the CuO2 -layers do not show any significant suppression of the specific heat a t T-c. Moreover, the specific heat above T-c, which is attributed to s uperconducting fluctuations, decreases. As a consequence the anomaly a t T-c appears to become sharper with increasing magnetic field.