Evolution of structural, magnetic and magnetocaloric effect in TmFe1-xMnxO3 (x≤0.3)

Abstract

The influence of Mn doping on structure, magnetic behaviors and magnetocaloric effect in TmFeO3 polycrystalline ceramics has been explored. X-ray powder diffraction proves that TmFe1-xMnxO3 (x ≤ 0.3) ceramics maintain an orthorhombic structure, and the space group is Pbnm. Compared with the original TmFeO3 sample, structural parameters change slightly and magnetic properties are effectively tuned with the gradual substitution of Mn at Fe site. The spin reorientation temperature region shifts from 90.3 to 73.2 K for TmFeO3 to 180.0–156.0 K for TmFe0.7Mn0.3O3. Besides, for TmFe1-xMnxO3 (x ≤ 0.3), the maximum magnetic entropy changes dependent on the Mn composition are 6.29 J/kg K, 6.56 J/kg K, 6.79 J/kg K and 7.22 J/kg K for 0–70 kOe, respectively. The refrigeration capacities are 159.3 J/kg, 168.9 J/kg, 176.7 J/kg and 184.4 J/kg, respectively. For a better assessing the magnetocaloric performance of TmFe1-xMnxO3 (x ≤ 0.3), we have calculated the temperature average entropy change, refrigerant capacity and normalized refrigerant capacity, and their values become larger with increasing Mn doping. Our experimental results can provide valuable references for the application and development of RFeO3 (R = rare earth) as multifunctional materials.