  We have revisited the magnetic structure of manganese phosphorus trisulfide
MnPS3 using neutron diffrac- tion and polarimetry. MnPS3 undergoes a transition
toward a collinear antiferromagnetic order at 78 K. The resulting magnetic
point-group breaks both the time reversal and the space inversion thus allowing
a linear magnetoelectric coupling. Neutron polarimetry was subsequently used to
prove that this coupling provides a way to manipulate the antiferromagnetic
domains simply by cooling the sample under crossed magnetic and electrical
fields, in agreement with the nondiagonal form of the magnetoelectric tensor.
In addition, this tensor has, in principle, an antisymmetric part that results
in a toroidic moment and provides with a pure ferrotoroidic compound.
