Reversible magnetocaloric effect and refrigeration capacity enhanced by two successive magnetic transitions in DyB2

A large and reversible magnetocaloric effect is found in the compound DyB2, which is associated with two successive magnetic transitions: a spin-reorientation-like transition followed by a ferromagnetic-paramagnetic transition. These two transitions appreciably enlarge the magnetic-refrigeration temperature window and yield a huge refrigeration capacity of 610 J kg(-1), with a maximum magnetic entropy change -Delta S-max of 17 J kg(-1)K(-1), at a magnetic-field change of 5 T. The corresponding values for low magnetic-field change of 2 T are 193 J kg(-1) and 7.4 J kg(-1)K(-1), respectively.