Neutron diffraction and Mössbauer study of the magnetic structure of YFe6Sn6

We have used time-of-flight (TOF) neutron powder diffraction, and both 57 Fe and 119 Sn Mössbauer spectroscopy over the temperature range 2–600 K to determine the magnetic ordering mode of the Fe sublattice in YFe6Sn6. The crystal structure is orthorhombic (space group Immm). The Fe sublattice orders antiferromagnetically with a Néel temperature of 558(5) K. The TOF neutron diffraction patterns obtained at 4 and 293 K show that the antiferromagnetic ordering of the Fe sublattice is along [100] with a propagation vector q=[010]. The magnetic space group is IPm′m′m′. This magnetic structure is confirmed by our 119 Sn Mössbauer spectra

Dietary Anthocyanins: Impact on Colorectal Cancer and Mechanisms of Action

5-nonemixedTramer F.; Moze S.; Ademosun A.O.; Passamonti S.; Cvorovic J.Tramer, Federica; Moze, S.; Ademosun, A. O.; Passamonti, Sabina; Cvorovic, Jovan

Lattice and spin dynamics in bcc Fe, 10 at. % Be

Body centered cubic Fe1−xBex alloys are known to display an enhanced tetragonal magnetostriction compared to Fe. In order to characterize the enhanced magnetoelasticity observed in this alloy system, we present detailed inelastic neutron scattering measurements of the phonon dispersion relations of a single crystal of bcc Fe, 10 at. %Be along the high symmetry directions [100], [110], and [111] at room temperature. We observe in particular that the frequency of transverse phonons propagating along the [110] direction with a [10] polarization at the zone boundary is reduced by 10% with respect to bcc Fe (the corresponding elastic shear constant c′ = ½(c11−c12) associated with this mode is approximately 70% that of pure Fe). The dispersion of spin waves has also been determined for energy transfers up to 40 meV and is found to follow the isotropic dispersion relation E(q) = Dq2, with D ∼ 200 meV/Å2 [for Fe, E(q) = Dq2, with D = 280 meV/Å2]

Kondo Effects and Multipolar Order in the cubic PrTr2Al20 (Tr=Ti, V)

Our single crystal study reveals that PrTr2Al20 (Tr = Ti and V) provides the first examples of a cubic {\Gamma}3 nonmagnetic ground doublet system that shows the Kondo effect including a -ln T dependent resistivity. The {\Gamma}3 quadrupolar moments in PrV2Al20 induce anomalous metallic behavior through hybridization with conduction electrons, such as T^{1/2} dependent resistivity and susceptibility below ~ 20 K down to its ordering temperature T_O = 0.6 K. In PrTi2Al20, however, quadrupoles are well-localized and exhibit an order at T_O = 2.0 K. Stronger Kondo coupling in PrV2Al20 than in PrTi2Al20 suppresses quadrupolar ordering, and instead promotes hybridization between the {\Gamma}3 doublet and conduction electrons, leading to most likely the quadrupolar Kondo effect.Comment: 12 pages, 4 figure