Effect of Dy, Ho, and Er substitution on the magnetocaloric properties of Gd-Co-Al-Y high entropy bulk metallic glasses

Glass-forming ability, thermal stability and magnetocaloric properties of Gd25Co25Al25Y25 and Gd25Co25Al25Y15RE10 (RE = Dy, Ho, and Er) high entropy metallic glasses are evaluated. With the substitution of Y by adjacent heavy rare earth elements, i.e., Dy, Ho, or Er, the critical dimension (Dc), the width of the supercooled liquid region, magnetic entropy changes (|ΔSM|) and refrigeration capacity (RC) increase obviously. However, the magnetic transition temperature (TC) almost keeps constant around 40 K, which may be attributed to the exchange interaction between Y and transition metal or other rare earth elements. Among resulting Gd25Co25Al25Y15RE10 metallic glasses, the peak values of |ΔSM| and RC can be improved from 6.76 to 7.35 Jkg−1K−1and 424 to 488 Jkg-1 when substituting Dy by Ho. This makes Gd25Co25Al25Y15Ho10 as an attractive candidate for magnetic refrigerants in hydrogen liquefaction temperature range.