Heat capacity and resistivity of Sm0.55Sr0.45MnO3 in magnetic fields of upto 26 kOe

Heat capacity and resistivity of Sm0.55Sr0.45MnO3 ceramics were measured ov er the temperature range 80-300 K in magnetic fields of up to 26 kOe. These quantities show anomalies caused by the magnetic and structural phase tran sitions. The critical temperature T-c and the heat capacity jump DeltaC(p)( T-c) at T-c increase with increasing applied magnetic field H, while the re sistivity decreases. The temperature dependences of the measured quantities show hysteresis, which is strongly suppressed in a field of 26 kOe but is sensitive nor to the temperature range neither to the rate of temperature c hange. The hysteresis of the heat capacity and resistivity of Sm0.55Sr0.45M nO3 is caused by a change in T-c with changing lattice parameters upon seco nd-order structural phase transition. The results are discussed in terms of the electron phase separation model. (C) 2000 MAIK "Nauka/Interperiodica".