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

Heat capacity and resistivity of Sm0.55Sr0.45MnO3 ceramics were measured over 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 transitions. 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 resistivity 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 change. The hysteresis of the heat capacity and resistivity of Sm0.55Sr0.45MnO3 is caused by a change in T-c with changing lattice parameters upon second-order structural phase transition. The results are discussed in terms of the electron phase separation model. (C) 2000 MAIK "Nauka/Interperiodica".