Magnetic and Magnetocaloric Properties of Pr0.8Bi0.2Fe x Mn1−x O3 Compounds with 0 ≤ x ≤ 0.3

Abstract

This paper studies the effects of the Mn site substitution by Fe on the magnetic properties and the magnetocaloric properties of Pr 0.8 Bi 0.2 Fe x Mn 1−x O 3 elaborated by a sol-gel method. The variation of the magnetization as a function of temperature and applied magnetic field was carried out. Magnetic measurements show that all the materials exhibit a paramagnetic-ferromagnetic transition when the temperature decreases. The dependence of the Curie temperature (T C ) and the magnetic entropy change ( S M ) when varying the Fe doping content was investigated. The measured value of T C was 114, 97, 94, and 77 K for x = 0, 0.1, 0.2, and 0.3, respectively. 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 firstorder phase transition. As the concentration of Fe increases, the maximum entropy change, S max M , 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.