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 Pr0.8Bi0.2Fe x Mn1−x O3 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 (ΔS M) 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, 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 first-order phase transition. As the concentration of Fe increases, the maximum entropy change, ${\Delta } S_{\mathrm {M}}^{\max }$ , 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.