Low Temperature Physics: 33, 264 (2007); https://doi.org/10.1063/1.2719964 (4 pages)
Fizika Nizkikh Temperatur: Volume 33, Number 2-3 (February 2007), p. 354-358 ( to contents , go back )
The effect of magnetic interactions on activation energy of polaron hopping conductivity of monocrystal manganite Eu0.6Sr0.4MnO3 in a paramagnetic phase
E.A. Neifeld, V.E. Arkhipov, N.A. Ugryumova, A.V. Korolyov, and Ya.M. Mukovsky
Institute of Metal Physics , S. Kovalevskoyi st. 18, Ekaterinburg 620219, Russia
Received September 22, 2006
The experimental data on electric resistance, thermopower, magnetization, and magnetic susceptibility a doped monocrystal manganite Eu0.6Sr0.4MnO3 in a paramagnetic phase are presented. The comparative analysis of the experimental dependence r(T) and the theoretical models used to described activation conductivity of manganites is carried out in a wide temperature range (80–400 K), in which a monotonous growth of the sample electric resistivity (approximately by six orders of magnitude) is observed. The r(T) behavior is most precisely described by the nearest neighbor hopping conductivity model of small radius adiabatic polarons, with activation energy decreasing with temperature. The qualitative explanation of the temperature dependence of activation energy is based on the fluctuation model of phase stratification with allowance made for magnetic contribution to activation energy offered by L.P. Gor’kov et al.
PASC: 72.80. Ga Transition-metal compound;
Key words: polaron hopping conductivity, manganite, specific electric resistance, magnetization, magnetic susceptibility.