Near room temperature magneto caloric effect in V doped La(0.67)Ca(0.33)MnO(3) ceramics

Abstract

La(0.67)Ca(0.33)MnO(3) doped with different amounts of V, resulting in the series La(0.67)Ca(0.33)Mn(1-x)V(x)O(3) [x = 0.03, 0.06, 0.1, 0.15, 0.25, 0.5] was synthesized by conventional solid-state ceramics route. Heat treatment conditions during synthesis were optimized to have small changes in the Curie temperature (T(C)). The compounds with x > 0.06 were found to have the additional LaVO(4) phase. A quantitative analysis of the extra phase with increase in V doping was investigated by the Rietveld refinement of the X-ray diffraction patterns. Variation of magnetic and magnetocaloric properties at different temperatures and magnetic fields was studied. Magnetocaloric effect has been studied in terms of isothermal magnetic entropy change (Delta S(M)). Magnetization was found to change drastically at around 275 K and the isothermal magnetic entropy change was found to peak in the temperature range 265-275 K. With increase in V content, Delta S(M) initially shows a considerable increase and then a decrease at higher V concentrations. (C) 2008