材料期刊网

Magnetic properties and magnetocaloric effect of the ferrimagnetic compounds Gd(4)Co(3) and (Gd(0.9)Dy(0.1))(4)Co(3) have been studied. In Gd(4)Co(3), two successive magnetic-entropy changes occur due to a spin-reorientation transition at T(SR)=163 K and a ferrimagnetic-magnetic ordering transition at T(C)=220 K. For a field change from 0 to 5 T, -Delta S(M)(max) at T(C) is 5.74 J/kg K, the full width at half maximum (delta T(FWHM)) of the -Delta S(M) versus T curve has a high value of 131 K, and the refrigerant capacity is as high as 575 J/kg. T(C) can easily be tuned by Dy substitution for Gd and the magnetic-entropy change is increased simultaneously. -Delta S(M)(max) of (Gd(0.9)Dy(0.1))(4)Co(3) at T(C)=145 K for the same field change has increased to 8.47 J/kg K. Our studies suggest that the successive magnetic transitions could enlarge the temperature interval, which makes this type of material meaningful for magnetic refrigeration in wider temperature regions than conventional materials.