| Abstract Scope |
Titanate-based hollandite-type materials with one-dimensional tunnel structures have attracted significant interest over the years. Their ability for charge transfer as well as radio nuclei immobilization, which are thermochemically antithetical properties, occurs as a function of A-site cation radii as previously demonstrated in our group. A series of hollandites of the form AxMgx/2Ti8-x/2O16 (A= Na, Cs, Na/Cs, K/Cs, K/Na), as synthesized via solid-state route, were varied in their A-site occupancy and subsequent cations. This work was founded on the hypothesis that increased A-site occupancy and larger cation radii enhance stability but reduce conductivity, due to the negative correlation between stability and conductivity in hollandites. The results of this work provide deeper insight into the fundamental underpinnings of A-site occupancy and cation radii to control the structure, thermodynamic stability, and physical properties of Mg-substituted hollandites, which facilitates the prediction and design of materials for solid electrolytes and immobilization applications. |