TbMgNi.sub.4-x./sub.Co.sub.x-./sub.(H,D).sub.2./sub. System. II: Correlation between Structural and Magnetic Properties

0574844 - ÚJF 2024 RIV US eng J - Journal Article
Paul-Boncour, V. - Beran, Přemysl - Hervoches, Charles - Shtender, V.
TbMgNi_4-xCo_x-(H,D)₂ System. II: Correlation between Structural and Magnetic Properties.
ACS Omega. Roč. 8, č. 33 (2023), s. 30727-30735. ISSN 2470-1343. E-ISSN 2470-1343
R&D Projects: GA MŠMT EF16_013/0001812
Research Infrastructure: CICRR - 90241
Institutional support: RVO:61389005
Keywords : magnetic properties * neutron powder diffraction * diffraction measurements
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 4.1, year: 2022
Method of publishing: Open access
https://doi.org/10.1021/acsomega.3c04879

The magnetic properties of TbMgNi4-xCox intermetallic compounds and selected hydrides and deuterides of this system have been studied by various techniques, including magnetic measurements, in situ X-ray and neutron powder diffraction. The intermetallic compounds crystallize in a SnMgCu4-type structure and magnetically order below a Curie temperature (T-C), which increases exponentially with the Co content. This can be due to the ordering of the Co sublattice. On the other hand, the insertion of D or H in TbMgNiCo3 strongly decreases T-C. The X-ray diffraction measurements versus temperature reveal cell volume minima at T-C for the compounds with x = 1-3 without any hints of the structure change. The analysis of the neutron diffraction patterns for the intermetallics with x = 2 and 3 indicates a slightly canted ferrimagnetic structure below T-C. The Tb moments refined at 16 K are 4.1(2) (mu B)/Tb for x = 2, and 6.2(1) mu B/Tb for x = 3, which are smaller than the free ion value (9.5 mu B/Tb). This reduction can be due to the influence of temperature but also reveals the crystal field effect. As Ni and Co occupy statistically the same Wyckoff site, an average Ni/Co moment was refined, leading to 1.7(2) (mu B)/atom for x = 2 and 1.8(1) mu B/atom for x = 3 at 16 K. This moment is slightly canted compared to the Tb moment.
Permanent Link: https://hdl.handle.net/11104/0344850