Magnetic ordering of TmSe under pressure

We report the first neutron diffraction study of the magnetic ordering in stoichiometric TmSe under pressures up to 20 kbar. The most striking result is the persistence of the type-I antiferromagnetic structure. We have observed the pressure dependence of the magnetic moment and of the Néel temperature; the temperature dependence of the sublattice magnetization (in reduced units) is independent of pressure. Comparisons are made with abnormal cerium compounds. © 1980.