True two-dimensional magnetic ordering in MnPS3

Neutron powder diffraction studies as a function of temperature on MnPS 3 have revealed temperature-dependent features inconsistent with the previously quoted magnetic ordering. The features vanish at approximately 12 K, a temperature well above the accepted Neel temperature of 78 K. The features are consistent with a true Ising-like two-dimensional ordering with the moments being antiferromagnetically coupled and pointing along the (010) direction.