Distinct spin glass behavior and excellent magnetocaloric effect in Er20Dy20Co20Al20RE20 (RE = Gd, Tb and Tm) high-entropy bulk metallic glasses

摘要

The Er20Dy20Co20Al20RE20 (RE = Gd, Tb and Tm) high-entropy bulk metallic glasses (HE BMGs) with tunable magnetocaloric properties were prepared successfully. As a result, a spin glass behavior was observed below 50 K in this HE BMG system. In addition, we found that the Curie temperature (T-c) can be easily tuned from 13 to 43 K by alloying different rare earth (RE) elements, following a good de Gennes factor dependence. The peak of magnetic entropy change (vertical bar Delta S-M(max)vertical bar) for Gd-, Tb- and Tm-containing glassy alloy under a magnetic field of 5 T is 9.1, 8.6 and 11.9 J kg(-1) K-1, respectively, which leads to obtain the maximum refrigerant capacity (RC) of 619, 525, and 405 J kg(-1) for the Er20Dy20Co20Al20RE20 (RE = Gd, Tb and Tm) HE BMGs, respectively. The glass forming ability (GFA), T-c, Delta S-M and RC can be widely tuned by alloying different RE elements. These results suggest that these HE BMGs are promising magnetic refrigerants at low temperature in the future.