New 5 K magnetic rare earth regenerator intermetallic compounds

The low temperature heat capacity of (Er1-xHox)In-3 alloys have been measured from similar to 3.5 to 350 K. The alloys are found to order antiferromagnetically between 4.45 K (ErIn3) and 8.0 K (HoIn3) The alloys, especially for 0 <= x < 0.7, have large volumetric heat capacities at the magnetic ordering temperature (as large as 1. 5 J/cm(3) K), and thus may be useful regenerator materials for cooling down to 4 K. The concentration dependence of the lattice constant, the magnetic ordering temperature, and the maximum value of the heat capacity are anomalous between x = 0.25 and x = 0.75 and do not follow a linear dependence between the two end members ErIn3 and Holn(3).