Magnetic and transport properties of Pr 0.8Ca 0.2MnO 3 crystal

Magnetic and transport properties of Pr _0.8Ca _0.2MnO ₃ crystal have been studied. It was found that the magnetic anisotropy in (1 0 0) plane increases with decreasing temperature and increasing pressure. The resistivity for T>140 K obeys Arrhenius law with an activation energy E_a=130 meV, while at T<130 K, E_a=62 meV. The magnetoresistance maximizes near the Curie temperature of Mn moments T_C1=130 K. The dynamic resistivity shows a marked dependence on a bias current I at T< T_C1. The results are discussed in the frame of magnetic phase separation and spin-density wave scenario.