Magnetic, transport, and electron magnetic resonance properties of Pr 0.8 Ca 0.2 MnO 3 single crystals Academic Article uri icon

abstract

  • Magnetic, transport, and electron magnetic resonance properties of Pr 0 , 8 Ca 0 2 MnO 3 single crystals have been investigated. Two ferromagnetic transitions observed at T C 1 130 K and T C 2 60 K, denote a long range ordering of Mn and Pr spins, respectively, and exhibit an opposite pressure coefficient for T C , dT C 1 /dP 0.24 K/kbar and dT C 2 /dP -0.75 K/kbar, respectively. The angular dependence of the magnetization in the (100) plane shows a strong twofold anisotropy, which increases under pressure. It was found that the resistivity ρ(T) obeys the Arrhenius law at 140 K≤T≤300 K with an activation energy E a =130 meV, whereas below T C 1 , E a =60 mev. The dynamic magnetoresistance vs magnetic field approaches a highest value of about 25% near T C 1 for H= 14.5 kOe. The dynamic resistance R d exhibits a pronounced dependence on a bias current I at T

publication date

  • January 1, 2003