Dielectrics and Conductors
The functionality of dielectrics and conductors most frequently lies in some form of molecular or ionic disorder. Accordingly, if we are to become able to tailor materials to suit a specific dielectric or (super)conducting application, we need to understand this disorder at the atomic and molecular level.
The most revealing of materials characterization approaches to quantify ionic or molecular disorder is X-ray or neutron diffraction. Specifically, a wealth of structural information can be drawn from the diffuse scattering features that surround Bragg positions in a crystal structure, in cases where disorder is prevalent. By capturing this information, we can start considering molecular design principles that will enable the molecular engineering of more advanced dielectric and conducting materials.
By way of a few examples, we have previously sought to unravel the nature of the disorder in chlorobenzene derivatives, which is responsible for their anomalous dielectric properties. We are currently investigating diffuse scattering signatures in a new class of superconductors (iron arsenides).
Physical Review B 2011 83 224202 (1-11)
Journal of Physics: Condensed Matter 2009 21 012208
Acta Crystallographica C 2008 64 0296-0302
Acta Crystallographica B: Structural Science 2007 63 663-673