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, ½ ], with kx equal to ¼ for R = Er and Tm or 0.3074   (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   K, are 6.5   (1)   μ B (Er) and 6.09   (4)   μ B (Tm), while in the incommensurate modulated magnetic structure in Ho2Ni1.78In the amplitude of modulation of the Ho magnetic moment is 7.93   (8)   μ 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 ł a, Baran, Hoser, Kalychak, Penc& 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 é el temperature of 4.5   K. Its magnetic properties are found to originate from...

Source: Acta Crystallographica Section B - September 18, 2021 Category: Chemistry Authors: Baran, S. Deptuch, A. Hoser, A. Penc, B. Tyvanchuk, Y. Szytu ł a, A. Tags: magnetic structure antiferromagnetism neutron diffraction magnetometric measurements symmetry analysis research papers Source Type: research