Solvent Extraction and Ion Exchange
Department or Program
crystallography, dielectric, diffuse reflectance, Lyonsite, magnetism
© 2020 Taylor & Francis Group, LLC. The lyonsite structure, characterized by the formula A 4 M 3O12, is a relatively understudied tunneled crystal structure. This host structure is known to be compositionally flexible, able to incorporate a number of cations in various oxidation states into the A site. In the parent compound Co3.75V1.5Mo1.5O12, it is apparent that a stoichiometric vacancy of 0.25 is unavoidable as a result of Coulombic repulsion. This work focuses on the systematic elimination of vacancies by chemically introducing guest Li ions while maintaining host integrity. A full solid solution was found to exist with the formula □0.25–1/8xLi x Co3.75–7/8xV1.5–3/4xMo1.5+3/4xO12 (0 ≤ x ≤ 2), terminating at the known end member Li2Co2Mo3O12. Lattice refinements on PXRD data confirmed the isostructural nature of the whole series, and detailed structural analysis revealed that competition between Li and Co in the same crystallographic site is unequal, with Li exhibiting a stronger site preference for larger interstitial sites. Diffuse reflectance analysis revealed that the optical band gap is directly tunable with x, and supporting structure-property relationships were also explored via magnetometry and dielectric measurements.
Joseph N. Tang, Dillon M. Crook, Geneva Laurita & M. A. Subramanian (2020) Vacancy Tuning in Li,V-Substituted Lyonsites. Solvent Extraction and Ion Exchange. 38(6) 656-680. https://doi.org/10.1080/07366299.2020.1780705
This is the author's version of the work. This publication appears in Bates College's institutional repository by permission of the copyright owner for personal use, not for redistribution.
Required Publisher's Statement
This is an Accepted Manuscript of an article published by Taylor & Francis in Solvent Extraction and Ion Exchange on September 18th, 2020, available online: http://www.tandfonline.com/10.1080/07366299.2020.1780705.