Size Effects on Charge Transport Mechanisms and Magnetotransport Properties of Pr0.67Sr0.33MnO3Nanoparticles

This paper covers a detailed study of the sintering temperature (T-S) effect on the electrical and magnetotransport properties of Pr(0.67)Sr(0.33)MnO(3)nanoparticles prepared by sol-gel method. The temperature dependence of resistivity displays a metal-insulator transition with increasing temperature. The electrical resistivity is strongly affected by particle size. The resistivity minimum at low temperature is associated to electron-electron coulombic interactions. Magnetotransport analysis was carried out using a phenomenological percolation model for all our samples. The obtained results indicate that a percolation model is not suitable for samples presenting high magnetic disorder. The magnetoresistance (MR) can be modulated by particle size effect. We have recorded considerable MR values (-MR(T) = 34% at 10 K for a 1Tfield whenT(S) = 850 degrees C, -MR(T) = 33% at 290 K for a 2Tfield whenT(S) = 1000 degrees C and -MR(H) = 33% at 5 K for a 1Tfield whenT(S) = 700 degrees C). The considerable MR values indicate the possibility of using these samples for several technological applications.