The magnetic phase transition in MnO

We have confirmed that the magnetic phase transition in MnO is first order at 117.5 ± 0.5 K. The sublattice magnetization curve appears to be of the general form appropriate for a critical phase transition up to a sudden drop to zero a few degrees short of the 'virtual' critical transition temperature. Our results do not show the anomalies on the nuclear Bragg peak at the transition temperature that were reported by Konstantinovic and Babic.