Magnetic and magnetocaloric properties of Pr0.8Bi0.2FexMn1-xO3 compounds with 0 ≤ x ≤ 0.3
Résumé
This paper studies the effects of the Mn site substitution by Fe on the magnetic properties and the magnetocaloric properties of Pr0.8Bi0.2FexMn1-xO3 elaborated by a sol-gel method. The variation of the magnetization as a function of temp. and applied magnetic field was carried out. Magnetic measurements show that all the materials exhibit a paramagnetic-ferromagnetic transition when the temp. decreases. The dependence of the Curie temp. (TC) and the magnetic entropy change (ΔSM) when varying the Fe doping content was investigated. The measured value of TC was 114, 97, 94, and 77 K for x = 0, 0.1, 0.2, and 0.3, resp. The samples with x = 0 and x = 0.1 present a second-order phase transition, while the samples with x = 0.2 and x = 0.3 exhibit a first-order phase transition. As the concn. of Fe increases, the max. entropy change,ΔSmaxM, decreases gradually, from 2.77 J kg-1 K-1 (x = 0) to 1.05 J kg-1 K-1 (x = 0.3), when the magnetic field changes from 0 to 5 T.