Crystalline structures of Rb$_2$UBr$_6$ ionic conductor determined by neutron diffraction

Krzysztof Małetka (1) , E. Ressouche (2) , Hakan Rundlof (3) , Rolland Tellgren (3) , Włodzimierz Szczepaniak (4) , Monika Zabłocka-Malicka (4)

1 National Centre for Nuclear Research [Otwock]
2 MDN - Magnétisme et Diffusion Neutronique
3 Uppsala University
4 Wroclaw University of Science and Technology

The neutron powder diffraction technique has been used for structural studies of Rb$_2$UBr$_6$ solid electrolyte as a function of temperature. The low-, room-, and high-temperature structures have been determined. At the temperature range of 4.2–80 K, the compound crystallizes in a monoclinic unit cell in the P21/c space group. At 80 K and 853 K, the compound crystallizes in a tetragonal unit cell in the P4/mnc space group. At 300 K, the lattice constants are a = b = 7.745(1) and c = 11.064(1) Å. At the temperature range of 853–960 K, a trigonal phase is observed in the P$\bar 3$ml space group.

Mots clés: Neutron diffraction; Ionic conductivity; Solid electrolyte; Phase transitions; Crystalline structure; Uranium bromide

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Krzysztof Małetka, E. Ressouche, Hakan Rundlof, Rolland Tellgren, Włodzimierz Szczepaniak, et al.. Crystalline structures of Rb$_2$UBr$_6$ ionic conductor determined by neutron diffraction. Nukleonika, 2020, 65 (1), pp.3-11. ⟨10.2478/nuka-2020-0001⟩. ⟨hal-02490544⟩