Influence of charge ordering on magnetocaloric properties of nanocrystalline Pr0.65(Ca0.7Sr0.3)0.35MnO3

Nanocrystalline Pr-0.65(Ca0.7Sr0.3)MnO3 show large magnetocaloric effect at their charge order transition temperature (T-CO) as well as at the temperature at which the spontaneous destabilization of charge ordered state occurs (T-M). In comparison to their polycrystalline bulk form, T-M's are substantially enhanced in the cases of nanocrystalline samples, whereas their T-CO's remain almost unchanged. Although there is no clear signature of charge order transition in the temperature dependence of magnetic susceptibility and resistivity for the sample with the lower particle size, a clear maxima due to charge order transition is visible in its temperature dependence of change in magnetic entropy. (c) 2008 American Institute of Physics.