
Intermediate Range Order in Metal–Ammonia Solutions: Pure and Na-Doped Ca-NH3
Author(s) -
Thomas C. Nicholas,
Thomas F. Headen,
Jonathan C. Wasse,
Christopher A. Howard,
Neal T. Skipper,
Andrew G. Seel
Publication year - 2021
Publication title -
the journal of physical chemistry. b
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 392
eISSN - 1520-6106
pISSN - 1520-5207
DOI - 10.1021/acs.jpcb.1c03843
Subject(s) - neutron diffraction , solvation , ion , chemistry , ammonia , metal , liquid ammonia , crystallography , short range order , doping , metal ions in aqueous solution , analytical chemistry (journal) , inorganic chemistry , materials science , crystal structure , chromatography , organic chemistry , optoelectronics
The local and intermediate range ordering in Ca-NH 3 solutions in their metallic phase is determined through H/D isotopically differenced neutron diffraction in combination with empirical potential structure refinements. For both low and high relative Ca concentrations, the Ca ions are found to be octahedrally coordinated by the NH 3 solvent, and these hexammine units are spatially correlated out to lengthscales of ∼7.4-10.3 Å depending on the concentration, leading to pronounced ordering in the bulk liquid. We further demonstrate that this liquid order can be progressively disrupted by the substitution of Ca for Na, whereby a distortion of the average ion primary solvation occurs and the intermediate range ion-ion correlations are disrupted.