Large magnetic entropy changes in Gd–Co amorphous ribbons

Abstract

A series of magnetic amorphous ribbons with different Gd/Co ratios was prepared by melt-spun method. With the decrease in Gd/Co ratio, Curie temperatures increase gradually from 166 to 193 K. The maximum values of magnetic entropy changes under a magnetic field of 10 kOe are −3.1, −3.0, −2.9, and −2.8 J/kg K for Gd71Co29, Gd68Co32, Gd65Co35, and Gd62Co38 samples, respectively. The approximately constant peak values of ΔSM at different working temperatures indicate that they are advantageous for an Ericsson refrigeration cycle. In addition, these samples have large resistivity and greatly reduced magnetic hysteresis losses, which could increase the refrigeration efficiency. These advantages make the Gd–Co amorphous ribbons good candidates for the practical magnetic refrigeration.