Anis Biswas

Modification of the charge ordering in Pr1∕2Sr1∕2MnO3 nanoparticles

Transport and magnetic properties have been studied in two sets of sol-gel prepared Pr1∕2Sr1∕2MnO3 nanoparticles having an average particle size of 30 and 45nm. Our measurements suggest that the formation of a charge-ordered state is largely affected due to lowering of the particle size, but the ferromagnetic transition temperature (TC) remains unaffected.

Experimental observation of charge ordering in nanocrystalline Pr0.65Ca0.35MnO3

Observation of charge ordering in single crystalline and bulk polycrystalline systems of various rare-earth based manganites is well documented. However, there is hardly any manifestation of the same when the grain size is reduced to nanoscale. We have observed charge ordering in case of nanocrystalline Pr

Magnetic and transport properties of nanocrystalline Nd0.5Sr0.5MnO3

_{0.65}

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

Ca

Magnetocaloric properties of nanocrystalline La0.125Ca0.875MnO3

_{0.35}

Observation of large low field magnetoresistance and large magnetocaloric effects in polycrystalline Pr0.65(Ca0.7Sr0.3)0.35MnO3

MnO

Evidence of a canted magnetic state in self-doped LaMnO3+δ (δ = 0.04): a magnetocaloric study

_{3}

Magnetocaloric properties of nanocrystalline Pr0.65(Ca0.6Sr0.4)0.35MnO3

of average particle size 40 nm. This phenomenon is attributed to the primary role played by the martensitic character of the charge order transition in the material.

Magnetotransport properties of nanocrystalline Pr0.65(Ca1−ySry)0.35MnO3(y∼0.4,0.3): Influence of phase coexistence

Nanocrystalline Nd0.5Sr0.5MnO3 of average particle size 30 and 55 nm are prepared by the sol-gel technique. Transport, magnetotransport, magnetization, specific heat, and current-voltage characteristics studies have been performed on the samples. Our experimental results indicate that the ferromagnetic transition temperatures of the nanocrystalline samples decrease in comparison with the bulk form of the sample. However, the ferromagnetic to charge ordered antiferromagnetic transition does not occur down to 2 K. The properties of the nanoparticles are discussed in detail which will provide a deeper insight into the physics of charge ordering and related phenomena in the rare-earth based manganites especially in their nanocrystalline form.

Inverse magnetocaloric and exchange bias?effects in single crystalline La0.5Sr0.5MnO3 nanowires

Nanocrystalline Pr0.65(Ca0.7Sr0.3)MnO3 show large magnetocaloric effect at their charge order transition temperature (TCO) as well as at the temperature at which the spontaneous destabilization of charge ordered state occurs (TM). In comparison to their polycrystalline bulk form, TM’s are substantially enhanced in the cases of nanocrystalline samples, whereas their TCO’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.