Influence of Pr-doping on structural, electronic transport, magnetic properties of perovskite molybdates Sr1-xPrxMoO3 (0 <= x <= 0.15)

摘要

The effect of Pr-doping on structural, electronic transport, magnetic properties in perovskite molybdates Sr1-xPrxMoO3 (0 <= x <= 0.15) has been investigated. The Pr-doping at Sr-site does not change the space group of the samples, but decreases the lattice parameter a. The magnitude of resistivity rho increases initially (x <= 0.08) and then decreases with further increasing Pr-doping level x and rho(T) behaves as T-2 and T dependence in the low-temperature range blow T* and high-temperature range of 150 K < T < 350 K, related to the electron-electron (e-e) and electron-phonon (e-ph) scattering, respectively. The magnetic susceptibility X value of the sample increases with increasing x and the X(T) curve for all samples can be well described by the model of exchange-enhanced paramagnetism. The specific heat magnitude in the low-temperature region increases with increasing Pr-doping level. The specific heat value agrees with the classical Dulong-Petit phonon specific heat, C-cl = 3k(B)rN(A) = 124.7 J/mol K in the high-temperature region and the temperature dependence of the specific heat can be well described by the formula C-p(T)/T = gamma(e) + beta(p)T(2) in the low-temperature range. These behaviors can be explained by the competition between the increase in the density of state (DOS) at Fermi energy level and the disorder effect due to Pr-doping, (c) 2006 Elsevier Ltd. All rights reserved.