Magnetic properties and magnetocaloric effects in R3Ni2 (R = Ho and Er) compounds

Magnetic and magnetocaloric properties of R3Ni2 (R = Ho and Er) compounds have been investigated. Both Ho3Ni2 and Er3Ni2 compounds undergo two successive phase transitions: spin reorientation transition and second-order ferromagnetic-paramagnetic transition. The maximal values of magnetic entropy change are achieved to be 21.7 J kg(-1) K-1 for Ho3Ni2 and 19.5 J kg(-1) K-1 for Er3Ni2 for a field change of 0-5 T. A large refrigerant capacity (RC) of 496 J kg(-1) in the composite material is also obtained. Large reversible magnetocaloric effect and RC indicate the potentiality of R3Ni2 (R = Ho and Er) compounds as candidates for low-temperature magnetic refrigerant. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3643142]