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

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.