Magnetic order of TmCu 2

Neutron diffraction experiments on two different polycrystalline TmCu2 samples were carried out on D1B (ILL, Grenoble) to determine the dependence of the magnetic order on temperature and on annealing state. In zero field at least three different magnetic phases are found: one commensurate antiferromagnetic structure with the propagation vector $\frac\Box5\Box\Box8\Box$ 00 and two types of magnetic order with the incommensurate propagation vectors (0.63300.018) and (0.6450.1270). The sample preparation strongly influences the magnetic order in the temperature region, where the squared-up commensurate and the incommensurate antiferromagnetic structures compete.