Exchange interaction and magnetoresistance in La2/3Ca1/3MnO3: Experiment and models Academic Article uri icon

abstract

  • The magnetization M(T) and electrical resistivity (T) of a La2/3Ca1/3MnO3 film have been studied in the temperature range 5 K T 320 K in the magnetic field intervals 10 Oe H 400 Oe and 0 H 50 kOe, respectively. It is found that the M(T)/M(0) value is larger than that predicted by the conventional molecular field model below the Curie point T = 267 K, and that the In (T) dependence is close to linear in the temperature range 80 K < T < 200 K (accordingly, ln /T is constant in this region). A model of the electrical conductivity and magnetoresistivity of the system describing qualitatively the experimental results is proposed (the m model). The model includes a thermally activated (with characteristic energy ) mechanism of conductivity, dependence of the concentration and the effective mass (m) of the itinerant charge carriers on the magnetization, as well as scattering (with characteristic time ) of the charge carriers by static breakings of the translational symmetry, thermal fluctuations of the magnetic order, and phonons.

published proceedings

  • Fizika Nizkikh Temperatur (Kharkov)

author list (cited authors)

  • Beznosov, A. B., Belevtsev, B. I., Fertman, E. L., Desnenko, V. A., Naugle, D. G., Rathnayaka, K., & Parasiris, A.

complete list of authors

  • Beznosov, AB||Belevtsev, BI||Fertman, EL||Desnenko, VA||Naugle, DG||Rathnayaka, KDD||Parasiris, A

publication date

  • July 2002