Heat Capacity, Entropy, and Intensity of Magnetization of MN(NH4)2(SO4)2·6H2O from 1 to 4°K in Fields up to 24 000 Oe Parallel to the b Axis

The magnetothermodynamic behavior of a spherical single crystal has been investigated from 1 to 4°K in fields up to 24 000 Oe parallel to the $b$ crystallographic axis ($K_3$ magnetic axis). The heat capacity of the specimen has been measured over this temperature range at five magnetic fields; these observations have been used in conjunction with the dependence of temperature with field along 16 isentropes to establish the entropy as a function of magnetic field and temperature. The intensity of magnetization has been measured as a function of field and temperature over the entire range. Deviations from ideal behavior are apparent in all measured properties, although smaller than in a specimen oriented perpendicular to the $b$ axis.