The magnetocaloric effect in high-spin paramagnetic rare-earth fluorites

Magnetic properties of single crystals of non-stoichiometric fluorides Cd0.90R0.10F2.10 (R = Gd, Tb, Dy and Ho) with the fluorite-type structure have been studied for the first time. Isothermal magnetization measurements were made at different temperatures. The magnetic entropy, the magnetic moment and the Curie temperature of these materials were investigated in a temperature range of 5–300 K. The samples are paramagnetic following the Curie–Weiss law in a wide range of temperatures. The results show quite a large magnetic entropy variation was achieved, suggesting a possible candidate for a magnetic refrigerator at temperatures below 20 K.