Magnetocaloric effect in metamagnetic borocarbide DyNi2 − xAxB2C (A = Co and Cr) compounds

The magnetic properties and magnetocaloric effect (MCE) in DyNi2 − xAxB2C (A = Co and Cr, x = 0.1, and 0.2) compounds have been studied. Substitution of Co or Cr for Ni lowered the magnetic transition temperature TM, and reduced the magnetic hysteresis of DyNi2B2C. An inverse MCE was observed, which is attributed to the nature of antiferromagnetic state under low magnetic field and at low temperatures for the present DyNi2 − xAxB2C compounds. A normal large MCE was observed under higher magnetic field changes, which is related to a field-induced first order meatmagnetic transition from antiferromagnetic to ferromagnetic state. The values of −ΔSMmax are 16.3, 10.2 16.1, and 13.7 J kg−1 K−1 with a magnetic field change of 5 T for x = 0.1 (Co), 0.2 (Co), 0.1 (Cr), and 0.2 (Cr) in DyNi2 − xAxB2C system, respectively. The magnetic transition, the origin of large MCE as well as its potential application in DyNi2 − xAxB2C system were discussed.

► The magnetocaloric effect in DyNi2 − xAxB2C (A = Co and Cr) have been studied.
► Substitution of Co or Cr for Ni reduced the magnetic hysteresis of DyNi2B2C.
► The origin of large MCE and its potential application in DyNi2 − xAxB2C were discussed.
► The present results may give some clue for searching new materials with large MCE.