Glass-Forming Ability and Magnetocaloric Effect in ${\rm Gd}_{55}{\rm Co}_{20}{\rm Al}_{25-{\rm x}}{\rm Si}_{\rm x}$ Bulk Metallic Glass

In this letter, we investigated the effect of Si addition on glass forming ability and magnetocaloric effect in Gd-Co-Al bulk glassy alloys. It is found that the addition of only 1 at.% or 2 at.% Si is effective for extension of the supercooled liquid region (ΔT_x) and decrease of the fragility parameter m. As a result, Gd-based glassy alloys with diameters up to 5 mm were successfully synthesized. The alloys also exhibit large MCE, i.e., having the magnetic entropy change (-ΔS_m) of 9.2 J kg^-1 K^-1, the full width at half maximum of the -ΔS_m (δT_FWHM) of 87 K, and the refrigerant capacity (RC) of 800 J kg^-1.