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

Heat capacity and resistivity of Sm_0.55Sr_0.45MnO₃ 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 ΔC _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 Sm_0.55Sr_0.45MnO₃ 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.