Shear Phase Inspired OxyFluorides (SPInOF)

Electronically conductive metal oxides represent an extremely important class of materials which underpin technologies from smartphones to efficient catalysts. Surprisingly, they are also rare. Discovering better conductive ceramics could accelerate breakthrough technologies such as spintronic devices for more efficient data storage. Despite their increasing importance, however, there is currently no systematic way to develop new metallic ceramics. The first aim of this project is therefore to create a family of new conductive materials by substituting oxygen for fluorine; namely metal oxyfluorides. Oxyfluorides offer the ability to directly tune the electronic properties of materials whilst preserving the same atomic structure. Specifically, this project will focus on substoichiometric “Magneli” phases where the atomic structure results in high electronic conductivity. These materials also undergo metal-to-insulator transitions as temperature is varied; such behaviour could be used in thermally activated devices (e.g. smart windows) but are also of fundamental scientific interest due to how they arise. Magneli-type oxides are a small but interesting class of materials, therefore Magneli oxyfluorides present an exciting family of materials waiting to be discovered.
Metal oxyfluorides offer chemical flexibility which could be harnessed in many other areas of materials chemistry such as magnetic materials or thermoelectrics, but their uptake has been hampered by difficulties in fully characterising their atomic structure (which underpins the observed properties). Despite these challenges, however, oxygen and fluorine have a strong tendency to adopt well-defined (cis- or fac-type) ordering around metal ions, offering additional influence over physical properties through the presence of “correlated disorder”. The second aim of this project is therefore to accurately determine the oxygen and fluorine arrangement in these new materials using detailed X-ray total...