Crystal and magnetic structures of R2Ni1.78In compounds R Tb, Ho, Er and Tm

The crystal and magnetic structures in R2Ni1.78In R Ho, Er and Tm have been studied by neutron diffraction. The compounds crystallize in a tetragonal crystal structure of the Mo2FeB2 type space group P4 mbm . At low temperatures, the magnetic moments, localized solely on the rare earth atoms, form antiferromagnetic structures described by the propagation vector k [kx, kx, ], with kx equal to for R Er and Tm or 0.3074 amp; 8197; 4 for R Ho. The magnetic moments are parallel to the c axis for R Ho or lie within the 001 plane for R Er and Tm. The obtained magnetic structures are discussed on the basis of symmetry analysis. The rare earth magnetic moments, determined from neutron diffraction data collected at 1.6 amp; 8197;K, are 6.5 amp; 8197; 1 amp; 8197; amp; 956;B Er and 6.09 amp; 8197; 4 amp; 8197; amp; 956;B Tm , while in the incommensurate modulated magnetic structure in Ho2Ni1.78In the amplitude of modulation of the Ho magnetic moment is 7.93 amp; 8197; 8 amp; 8197; amp; 956;B. All these values are smaller than those expected for the respective free R3 ions. A symmetry analysis of the magnetic structure in Tb2Ni1.78In is also included, as such information is missing from the original paper [Szytu amp; 322;a, Baran, Hoser, Kalychak, Penc amp; Tyvanchuk 2013 . Acta Phys. Pol. A, 124, 994 997]. In addition, the results of magnetometric measurements are reported for Tm2Ni1.78In. The compound shows antiferromagnetic ordering below the N el temperature of 4.5 amp; 8197;K. Its magnetic properties are found to originate from magnetic moments localized solely on the thulium atoms the nickel atoms remain non magnetic in Tm2Ni1.78In . The reduction of rare earth magnetic moments in the ordered state in R2Ni1.78In R Tb, Ho, Er and Tm and the change in direction of the moments indicate the influence of the crystalline electric field CEF on the stability of the magnetic order in the investigated compound

The scandium effect in multicomponent alloys

Despite its excellent elemental properties, lightweight nature and good alloying potential, scandium has received relatively little attention in the manufacturing community. The abundance of scandium in the Earth's crust is quite high. It is more abundant than silver, cobalt, lead and tin. But, because scandium is so well dispersed in the lithosphere, it is notoriously difficult to extract in commercial quantities – hence low market availability and high cost. Scandium metallurgy is still a largely unexplored field – but progress is being made. This review aims to summarise advances in scandium metallurgical research over the last decade. The use of scandium as a conventional minor addition to alloys, largely in structural applications, is described. Also, more futuristic functional applications are discussed where details of crystal structures and peculiar symmetries are often of major importance. This review also includes data obtained from more obscure sources (especially Russian publications) which are much less accessible to the wider community. It is clear that more fundamental research is required to elevate the status of scandium from a laboratory-based curiosity to a mainstream alloying element. This is largely uncharted territory. There is much to be discovered