Flux Synthesis of Alkaline-Earth Lanthanide Borates as Potential Nuclear Waste Forms

Author(s)

Gregory Morrison
Adrian T. Hines
Virginia G. Jones
K. Pilar Zamorano
Ethan N. Adams
Mark D. Smith, University of South CarolinaFollow
Hans Conrad zur Loye, University of South CarolinaFollow

Document Type

Article

Abstract

Neodymium is typically considered the best surrogate for trivalent americium and can be used to identify Am³⁺ containing materials that are likely to form. We have explored the alkaline-earth lanthanide borate phase space using alkaline-earth halide/carbonate fluxes. This resulted in the synthesis of new compounds AE₅Ln(BO₃)₄X (AE = Ca, Sr; Ln = Pr, Nd, Eu, Tb; X = Cl, Br) and AE₃Ln₂(BO₃)₄ (AE = Sr, Ba; Ln = Pr, Nd) as well as the synthesis of two compounds of Ba₈Ln₂(BO₃)₆(B₂O₅) (Ln = Eu, Tb) crystallizing in a new structure type. Ba₈Ln₂(BO₃)₆(B₂O₅) crystallizes in the space group P21/n with lattice parameters a = 8.6002(3) Å, b = 7.9245(3) Å, c = 17.6697(7) Å, and β = 91.3560(10)° for the Eu analogue, and the structure contains isolated LnO₈ polyhedra connected into a framework by BO₃ and B₂O₅ units. The fluorescence emission spectra of AE₅Ln(BO₃)₄X (AE = Ca, Sr; Ln = Eu, Tb; X = Cl, Br) and Ba₈Ln₂(BO₃)₆(B₂O₅) (Ln = Eu, Tb) are reported.

Digital Object Identifier (DOI)

https://doi.org/10.1021/acs.inorgchem.4c02297

Publication Info

Published in Inorganic Chemistry, Volume 63, Issue 33, 2024, pages 15359-15367.

Rights

© 2024 American Chemical Society

APA Citation

Hines, Jones, Smith, & zur Loye (2024). Flux Synthesis of Alkaline-Earth Lanthanide Borates as Potential Nuclear Waste Forms. Inorganic Chemistry, 63(33), 15359–15367. https://doi.org/10.1021/acs.inorgchem.4c02297