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.
Crystallographic data and magnetic properties of RT6Ge6 compounds (R Sc, Y, Nd, Sm, GdLu; TMn, Fe)
Abstract The iron and manganese germanides RT 6 Ge 6 (RSc, Y, Nd, Sm, GdLu; TMn, Fe) have been investigated by X-ray diffraction and susceptibility measurements in the temperature range 90–900 K. They crystallize in the known HfFe 6 Ge 6 , YCo 6 Ge 6 , TbFe 6 Sn 6 or HoFe 6 Sn 6 type of structure except GdFe 6 Ge 6 which is of a new type. All the compounds are anti-ferromagnetic except the RMn 6 Ge 6 (RNd, Sm, Gd) compounds which behave ferrimagnetically. Weak coercive fields (down to 1 kOe) are measured in RMn 6 Ge 6 (RNd, Sm).
155Gd mössbauer effect in AlB2-type GdGa2-xAlx compounds
Abstract We have investigated the effect of Al substitution on the lattice constants and 135 Gd Mossbauer spectra of GdGa 2 . Marked changes were observed in the values of the electric field gradient derived from the quadrupole splitting of the spectra, changing from positive to negative for x > 0.5 in GdGa 2 -x Al x . This was ascribed to the concomitant change in nearest-neighbour configuration of the Gd atoms in this series, as deduced from the jump-like change in lattice parameters around x =0.5. The variation in V zz across the series GdGa 2-x Al x is discussed in relation to the second-order crystal field parameter A 2 0 which shows a similar variation and sign reversal.