Abstract
The specific heat of a single-crystal sample of MnCl2 has been measured, in the liquid-helium temperature region, in applied magnetic fields extending up to 7.26 kOe. In all cases the magnetic field was applied parallel to an a axis of the hexagonal cell. The two specific heat maxima, which have been previously reported at 1.81 and 1.96°K in zero field, are associated with antiferromagnetic transitions. Both transition temperatures are found to be field dependent. The upper transition temperature increases with applied field while the lower transition temperature decreases. These results are correlated with neutron diffraction studies of the magnetic structure transitions.