Magnetic and magnetocaloric properties of TbMnO3 and Tb0.67R0.33MnO3 (R=Dy, Y, and Ho) bulk powders

Orthorhombically distorted perovskite rare-earth manganites with smaller rare-earth ions, such as TbMnO3, have mostly been explored for their multiferroic properties. In this work, magnetic and magnetocaloric properties in both TbMnO3 and A-site substituted Tb0.67R0.33MnO3 (R=Dy, Y, Ho) powder samples, prepared via solution route, were investigated. A weak ferromagnetic component was observed in the dc magnetic data of Dy- and Ho-substituted TbMnO3 that may be due to the change in average ionic radius at the A-site (Tb-site) as well as the larger magnetic moment of the substituting ion (~10.6 μB for Dy3+ and Ho3+ as compared to 9.7 μB for Tb3+). The magnetic entropy was found to decrease with the dilution of the Tb3+ ordering by the introduction of both magnetic and non-magnetic dopants at the A-site. Magnetocaloric properties of these samples were evaluated and for pure TbMnO3, a maximum relative cooling power of ~103 J/kg with 5 T applied field was observed that shows its potential for magnetic refrigeration.