Magnetic field-induced transitions in La0.42Eu0.25Ca0.33MnO3 perovskite manganite

Abstract

Electrical and magnetic transport properties of polycrystalline La0.42Eu0.25Ca0.33MnO3 manganite perovskite are reported here. Temperature dependence of electrical transport, in 0 and 0.6 T external magnetic fields, shows insulating behaviour down to the lowest measured temperatures. Application of 6 T external magnetic field induces two different transitions: (1) an insulator–metal transition around 110 K and (2) a low temperature upturn in resistance values at 30 K. These field-induced transitions suggest strong competition between various interactions present in these materials; this is further supported by the observation of hysteresis in electrical resistance in thermal cooling and warming cycles of measurement. The observed upturn in resistance values below 30 K is presumably due to the combined effect of weak localization, electron–electron and electron–phonon scattering. Magnetization measurements show a paramagnetic–AFM transition at 50 K, but a deviation from a straight line in the 1/M versus T is observed well above 170 K. These results manifest the competition between various possible interactions present in the system.