solid state and materials chemistry



Our research is directed towards understanding structure-property relationships in metal oxides, and in particular understanding how small charges in composition can have significant impact of chemical and physical properties.  Our major methodology is powder diffraction, using X-rays (in-house and synchrotron), neutrons and when desperate electrons.  These studies are supplemented by X-ray and electron spectroscopy and magnetic measurements.

Project 1

Hosts for inorganic wastes – from dentists to Fukushima
The disaster at the Fukushima Dai-ichi nuclear plant has again highlighted the need to develop selective and stable hosts for metal ions, be they nuclear or heavy metal wastes.  This work will look at two approaches to the problem.  Firstly how good are synthetic mimics of natural hosts?  This will focus on preparing and characterising chemically doped apatites – the natural mineral component of bone and teeth.  The second approach explores the need for flexibility in the host and in this work we will look at samples near a pyrochlore-fluorite transition.


Project 2

Cathodes for solid oxide fuel cells
One of the major impediments to the use solid-oxide fuel cells (SOFC) as economically viable energy-conversion devices is their high operating temperature.  The challenge is to decrease the operating temperature (550-850 °C) without a loss in the effectiveness of the cell. The cathode is responsible for a significant drop in the cell potential at intermediate temperatures (650-850 °C), therefore the development of a mixed ionic electronic conductor (MIEC) oxide performing as a cathode with an appropriate conductivity and catalytic activity in the oxygen reduction reaction is an important issue in solid state chemistry.  This project will explore the possibility of using non-stoichiometric Bi containing pyrochlores as cathodes for SOFC


Project 3

Crystallographic phase transitions
Our ability to tune chemical composition through the formation of solid solutions should allow us to also tune the structure.  However despite our best intentions anomalies persist and we simply do not have a sufficient body of information to predict phase transitions.  In this project we focus on the preparation of perovskite-type materials that exhibit desirable properties (ferroelectrics, magnetism etc) and study how there structures evolve as we change their environment (temperature, pressure).

 


For further information, please contact:

Professor Brendan Kennedy

Room 458

School of Chemistry

Eastern Avenue

University of Sydney NSW 2006

Phone: +61 2 9351 2742

Email: brendan.kennedy@sydney.edu.au