Professor Derek C. Sinclair
Department of Materials Science and Engineering
University of Sheffield

Abstract

Oxide-based perovskites (general formula ABO3) exhibit a diverse and impressive range of functional properties (eg superconductivity, ferroelectricity, fast-ion conductivity, mixed ionic-electronic conductivity) and find applications in many ceramic-based devices, eg multi-layer ceramic capacitors/actuators and solid oxide fuel cells. Here we will review the diverse range of electrical properties that can be displayed by titanate-based perovskites, based on different A-site cations and low levels of non-stoichiometry and/or aliovalent doing. This will include a research efficient method to produce high permittivity bi-layers of BaTiO3-based materials for multi-layer ceramic capacitors and, A- and O-site deficiency in Na1/2Bi1/2TiO3 (NBT) and La-doped SrTiO3 (LST) to induce solid electrolyte behaviour suitable for intermediate temperature Solid Oxide Fuel Cells (NBT) and high electronic conductivity and low thermal conductivity for n-type legs for thermoelectric generator (LST).

Biography

Derek C. Sinclair is Professor of Materials Chemistry at the Department of Materials Science & Engineering at the University of Sheffield. He has been involved in the synthesis and characterisation of functional materials and devices for >25 years and has a strong track record elucidating structure-property relationships in a variety of material types with particular expertise in chemical doping to manipulate defect chemistry and conduction mechanisms of perovskite-based oxides for energy applications (h =48, > 11,000 citations, Google Scholar). The range of functionality studied spans from polar dielectrics, n-type thermoelectrics to mixed electronic/ionic conductors and solid electrolytes. He has co-authored with Julian Dean and John Harding new approaches to simulate Impedance Spectroscopy data using finite element modelling of heterogeneous electrical microstructures created by grain size/shape distribution and grain core-shell effects. He works with Industry, for example a Knowledge Transfer Project with AVX Ltd (Coleraine, NI) led to a new range of BaTiO3-based X8R Multi-layer ceramic capacitors (~ £8 M in sales since 2012). He is an Editor for the Journal of the Asian Ceramic Societies (JAsCerS) for the Ceramic Societies of Japan and Korea.