Magnetic Properties of Praseodymium in Magnetic Fields Determined from the Nuclear Heat Capacity and Applied to Nuclear Cooling

The nuclear heat capacity of praseodymium in fields from 0 to 18.6 kOe has been measured from 16 to 300 mK. In zero field the metal was found to be ordered with average magnetic moments of 0.62${\mathrm{\mu }}_{\mathrm{B}}$ and 0.05${\mathrm{\mu }}_{\mathrm{B}}$ on the two inequivalent lattice sites. Above 10 kOe the Van Vleck behavior dominates and an induced moment appears on both sites. The corresponding induced hyperfine field has been employed for nuclear cooling.