Crossover Effect of Magnetotransport and Magnetocaloric Effect in (La0.7ba0.3mno3)1-X/(al2o3)x Composites

Magnetotransport properties and magnetocaloric effect of (La0.7Ba0.3MnO3)(1-x)/(Al2O3)(x) composites have been investigated through their theoretical and experimental studies. The Al2O3 addition increases the resistivity, showing up a crossover from 3D Mott to the soft gap variable range hopping (VRH). The relative cooling power of LBMO matrix (similar to 98.77 Jkg(-1), H = 2 T) is approximately 65 percentage of that of pure Gd (RCP = 153 Jkg(-1), H = 2 T). It means to achieve an active magnetic refrigerator employing LBMO will need more than one and half times the volumes of a refrigerant unit consisting of pure Gd. A good concordance is observed as simulated both resistivity and magnetization curves.