Investigation of Fluoroacidity in Molten Fluorides by the Combination of High Temperature NMR and Molecular Dynamics

Abstract

The acidity of a molten salt will act directly on the formation of complexes involving the cations of the melt. The determination of the speciation with varying overall composition therefore provides an indirect measure of the acidity. This opens a route for building up the acidity scale through the use of some specific in situ spectroscopic approaches. To determine the speciation in the liquid state, Nuclear Magnetic Resonance (NMR) appears as the ideal candidate, as it allows estimating the relative concentration of the various complexes formed in the melt. In parallel, Molecular Dynamics (MD) simulations are the unavoidable complement to this experimental technique. In this work we describe the structure and the dynamics in the LiF-CaF2 system.

High-precision nuclear magnetic resonance probe suitable for in situ studies of high-temperature metallic melts

“…[38,39] with higher sensitivity, a stronger RF field, and a better homogeneity instead of a saddle-shaped RF coil used in previous laser-heating probes. [30,40] Herein, the RF coil of our high-temperature probe is a 7-turn solenoid with an inner diameter of 6 mm, as shown in Figs. 1(c) and 1(d).…”