Electronic and magnetic phase transitions in (Sm 0.65Sr 0.35)MnO 3 induced by temperature and magnetic field

Abstract

Temperature (4.2–260 K) and magnetic field (0–50 kOe) dependencies of the DC electrical resistance, DC magnetization, and AC magnetic susceptibility of (Sm 0.65Sr 0.35)MnO 3 prepared from high purity components have been studied. (Sm 0.65Sr 0.35)MnO 3 undergoes a temperature-induced transition between low-temperature ferromagnetic metallic and high-temperature paramagnetic insulating-like states. A magnetic field strongly affects this transition resulting in a metallic state and “colossal” magnetoresistance in the vicinity of the metal↔insulator transition. Magnetic and electric properties of (Sm 0.65Sr 0.35)MnO 3 are different compared to those reported earlier for similar composition, which is attributable to the purity of the starting materials and/or different process of synthesis. The character of phase transformations observed in (Sm 0.65Sr 0.35)MnO 3 is compared to that reported for Gd 5(Si x Ge 4− x ) intermetallic alloys with a true first order phase transition.