Minimization of temperature reached by adiabatic demagnetization refrigeration in Ce-based intermetallic Ce2(Cu1<b>−</b> <i>x</i>Ni<i>x</i>)2In

Abstract

Magnetic entropy remaining near absolute zero temperature in the antiferromagnetic (AFM) critical state is expected to be usable for the cryogenic magnetic refrigeration. In this paper, we report quasi-adiabatic demagnetization refrigeration for Ce2(Cu1−xNix)2In (0≤x≤0.38) whose parent compound Ce2Cu2In orders antiferromagnetically below 6 K, by using a laboratory-made cell attachable to a commercial 4He refrigerator with a base temperature of 1.8 K. The final temperature by the quasi-adiabatic demagnetization as a function of x indicates a local minimum of 1 K at the AFM critical composition of x∼0.3. The validity of this result is confirmed by our specific-heat measurements. Our work motivates the future developments of Ce-based cryogenic magnetic refrigerants with the lower characteristic temperature in view of the low cost and easiness in synthesizing compared with Yb-based counterparts.