Investigation of Magnetocaloric Behavior of Nanocrystalline Nd0.67A0.33MnO3, (A = Ca, Sr, Ba and Pb)

Colossal magnetoresistive (CMR) materials with the compositional formula, Nd(0.67)A(0.33)MnO(3) (where A = Ca, Sr, Ba, and Pb) in the nanocrystalline form were prepared by the PVA gel technique. After characterizing the samples structurally, a systematic investigation of magnetization has been undertaken, over a temperature range 10-300 K at 0.05 T magnetic field. An effort has been made to calculate the magnetocaloric behavior of all the samples theoretically using the experimental magnetization data. Other important parameters such as maximum entropy change, full width at half-maximum, relative cooling power, and maximum adiabatic temperature change under 0.05 T were also computed. The observed behavior has been explained qualitatively.