Magnetism of YMn6Sn6 and DyMn6Ge6: Single-crystal Study
The magnetic properties of YMn6Sn6 and DyMn6Ge6, which crystallize in the hexagonal HfFe6Ge6-type of structure, have been studied on single crystals that have been prepared in an Sn flux and In flux, respectively. The compounds order antiferromagnetically at about 330 K and 450 K and exhibit very complex magnetic properties in the magnetically ordered state. The evolution of the magnetization in the ordered state has been investigated in the temperature region from 2 to 550 K and magnetic field up to 14 T.
Neutron study of the magnetic structure change in DyMn6Ge6
Abstract The hexagonal compound DyMn 6 Ge 6 has been studied by neutron diffraction at various temperatures between T N = 420 K and 11 K. The magnetic structure is incommensurate at all temperatures in the ordered regime with q = (0, 0, q z ). The corresponding wavevector component q z decreases strongly on cooling to about T t = 100 K. It remains almost temperature independent ( q z = 0.1631) below T t at which temperature a second set of Fourier components with q = 0 appears. The phase transition at about 100 K is shown to be of second order and marks the transition from a triple flat spiral structure stable at high temperatures to a triple conical structure stable at low temperatures. The origin of the phase transition is the competition between the temperature-dependent Mn and Dy sublattice anisotropies.
Crystal structures of RFe6Sn6 (R = Sc, Y, GdTm, Lu) rare-earth iron stannides
Abstract A new X-ray powder diffraction study of RFe6Sn6 (R=Y, GdTm,Lu) compounds points out the occurrence of a long range ordering in these previously reported YCo6Ge6 type structure compounds. LuFe6Sn6 and TmFe6Sn6 are found to be isotypic with HfFe6Ge6. The other compounds have new related type structures compounds which consist of different intergrowths of HfFe6Ge6 and ScFe6Ga6 - ordered variant of ThMn12 - slabs.