Abstract
We have investigated the magnetocaloric effect along with magnetic phase transition and critical exponent analysis in mixed manganite La0.67Sr0.33Mn1−xVxO3 (0≤x≤0.15). To determine the nature of the paramagnetic to ferromagnetic phase transition, found to be of second-order, we performed a critical exponents study by dc-magnetization M(H,T) measurements around the Curie temperature TC. Modified Arrott plot method has been adopted to study the critical behavior of the compounds at their transition region, the values of critical exponents β, γ and δ are close to those expected for three-dimensional Heisenberg class with short-range interaction. A large magnetic entropy change |ΔSM| deduced from isothermal magnetization curves, has been observed in our samples with a peak centered on their respective TC. With increase in vanadium content, the temperature corresponding to the maximum entropy change as well as the magnetic transition temperature gradually shifts to low temperatures. The field dependence of the magnetic entropy change is also analyzed, which shows the power law dependence namely, ΔSM∝Hn. Relative cooling power increases from 205J/kg for x=0.00 to 258J/Kg for x=0.15 making these materials a promising candidates for magnetic refrigeration near room temperature.
Scaling plot below and above TC using the β and γ exponents determined from the Arrot plot method of La0.67Sr0.33Mn1−xVxO3 for x=0.15. [Display omitted]
•The paramagnetic to ferromagnetic phase transition of La0.67Sr0.33Mn1−xVxO3 (0≤x≤0.15) is found to be of second-order.•The field dependence of the magnetic entropy shows the power law dependence namely, ΔSM∝Hn.•Moderate values of −ΔSMmax and RCP make the La0.67Sr0.33Mn1−xVxO3 compounds potential candidates for magnetic refrigeration applications.