Vanadium-doping effects on magnetic and magnetocaloric efficiency of La 0.7 Sr 0.2 (CaLi) 0.05 Mn 1− x V x O 3 [ x = 0.00 and x = 0.05] manganites

The La0.7Sr0.2Ca0.05Li0.05Mn1−xVxO3 [S1(x = 0) and S2(x = 0.05)] polycrystalline compounds are found to exhibit a ferromagnetic—paramagnetic transition (FM–PM) when temperature increases with a decrease of Curie temperature TC when substituting Mn with V from TC = 271 K to TC = 266 K. The Arrott plots near Curie temperature show positive slopes under an applied magnetic field varying from 0 to 5 T showing a second order magnetic transition for our samples. Basing on the magnetic-field dependences of magnetization measured around TC, maximum magnetic-entropy changes \(\left| {\Delta S_{M}^{{\hbox{max} }}} \right|,\) under the applied field of 5 T, are about 5.4 and 4.8 J kg−1 K−1 for S1 and S2 respectively. The efficiency of our samples for magnetic refrigeration application has been evaluated throw calculating the relative cooling power (RCP) values, which were equal to 211.5 J kg−1 for S1 and 195.5 J kg−1 for S2. The study of the universal curves show that the rescaled magnetic entropy change curves for different applied fields collapse onto a same curve confirming that both S1 and S2 reveal a second order transition.