The University of Sheffield
Department of Materials Science and Engineering

Professor John Harding

Prof J Harding

MA PhD FRCS FinstP
Professor of Materials Simulation

Address:
Department of Materials Science and Engineering
Sir Robert Hadfield Building
Mappin Street, Sheffield, S1 3JD

Telephone: +44 (0) 114 222 5957
Fax: +44 (0) 114 222 5943

Email: j.harding@sheffield.ac.uk

John Harding joined the Department in 2004 from the Department of Physics and Astronomy, University College London.

Research interests

Real crystals stop somewhere and the boundaries, whether surfaces, grain boundaries or more complex interfaces often determine the behaviour. This is particularly true for nanomaterials, where a significant fraction of the atoms are at a boundary. The way crystals grow, their shape and structure is determined by the local environment.
The most spectacular example of this is the ability of living systems to grow minerals in complex shapes and sometimes unusual phases. Often, biominerals are nanocomposites – the combination of organic scaffold and mineral produces a material with unusual properties – for example the hardness of tooth enamel. We work closely with experimental groups, using simulations to understand how biomaterials are formed. This work is currently funded through an EPSRC programme grant "Hard-soft materials: from understanding to engineering" and involves collaborations both within Sheffield, nationally and internationally. Further details can be found on the link below.
We are also simulating the properties of interfaces as part of an EU programme to develop a multi-scale modelling framework for solar cells (Hipersol). This requires understanding the properties of the interfaces between the silver contact and silicon and also between the passivation layer and silicon and integrating this into a model of the solar cell. Further details can be found on the Hipersol link below.
The bulk properties of crystals, particularly transport properties, are often determined by point defects, either intrinsic, deliberately added or just happen to be there. Understanding the behaviour of defects, interfaces and how they control crystal properties needs simulation at the atomic scale (and often at longer scales as well). We use simulations to understand the properties of a variety of electroceramics, working with other members of the Ceramics and Composites Laboratory. A combination of atomistic and finite element methods is used to understand experimental impedance data.
Simulations are also being used to help develop new materials for encapsulating high-level nuclear waste by looking at the effects of radiation damage on several candidate materials in collaboration with Daresbury Laboratory and the University of Bristol.
The group therefore use a variety of methods: static lattice calculations, molecular dynamics, kinetic Monte Carlo, quantum (ab initio) methods, mesoscale (coarse-grained) and finite element simulations in conjunction with experiment to try and understand materials at all appropriate length and timescales.

Key projects

Professional activities and recognition

Key publications

Research group

Research Assistants (postdocs)
Dr Colin Freeman
Dr Keith Butler
Dr Julian Dean
Dr Henry Foxhall (jointly with Dr Karl Travis)
Dr Bo Christiansen (in collaboration with Prof. Susan Stipp, University of Copenhagen)

Research students
Mr Hungru Chen
Mr James Dawson
Mr David Sparkes

Research themes/centres

Nanomaterials and nanoengineering

Computer modelling and simulation

Immobilisation Science Laboratory

Ceramics and Composites Laboratory

Cell-mineral research centre

Teaching

Links

EPSRC atomistic simulation network CCP5

Programme Grant: “Hard-soft interfaces: from understanding to engineering"

Materials Chemistry Consortium

Hipersol project

MESAS (Multiscale Engineering and science Simulations at Sheffield)