- Attila Bartha: Single crystal study of layered UnRhIn3n+2 materials: case of the novel U2RhIn8 compound
- 25. 2. 2015, 14:50
- lecture room F2, first floor Ke Karlovu 5
- more information
Abstract:
We report on the single crystal properties of the novel U2RhIn8 compound studied in the context of parent URhIn5 [1] and UIn3 [2] systems. The compounds were prepared by In self-flux method. U2RhIn8 adopts the Ho2CoGa8-type structure with lattice parameters a = 4.6056(6) Å and c = 11.9911(15) Å. The behavior of U2RhIn8 strongly resembles that of related URhIn5 with respect to magnetization, specific heat and resistivity showing strong magnetocrystalline anisotropy. U2RhIn8 orders antiferromagnetically below TN = 117 K and exhibits slightly enhanced Sommerfeld coefficient γ = 47 mJ.mol-1.K-2. TN increases with increasing c/a ratio within the UIn3 – UrhIn5 – U2RhIn8 series contrasting with the behavior of the cerium counterparts. Magnetic field leaves the value of Néel temperature for both URhIn5 and U2RhIn8 unaffected up to 9 T. On the other hand, TN increases with applying hydrostatic pressure up to TN = 126 K at 3.2 GPa. The character of uranium 5f electron states of U2RhIn8 was studied by first principles calculations based on the density functional theory combined with the Hubbard model. The overall phase diagram of U2RhIn8 is discussed in the context of magnetism in related UnTX3n+2 and UX3 (n = 1, 2; T = transition metal, X = In, Ga) compounds [3, 4, 5].
References:
[1] Y. Matsumoto et al., Phys. Rev. B 88 (2013) 045120
[2] Y. Tokiwa et al., J. Phys. Soc. Jpn. 70 (2001) 3326
[3] S. Ikeda et al., Physica B 359 (2005) 1039
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[5] P. Boulet et al., Solid State Commun. 107 (1998) 135