Professor John Harding


Department of Materials Science and Engineering

Professor of Materials Simulation
+44 114 222 5957

Full contact details

Professor John Harding
Department of Materials Science and Engineering
Sir Robert Hadfield Building
Mappin Street
S1 3JD

John Harding joined the Department in 2004 from the Department of Physics and Astronomy, University College London having previously worked at Harwell from 1978 to 1995.

Research interests

Real crystals stop somewhere and the boundaries, whether surfaces, grain boundaries or more complex interfaces often determine the behaviour of materials. 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. I am a member of a consortium of Universities (Leeds, Sheffield, UCL, Warwick) that is investigating the mechanisms of crystallisation using both simulation and experiment.

The most spectacular example of controlling crystallisation 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 – eg. the hardness of tooth enamel. We work closely with experimental groups, using simulations to understand how biomaterials are formed and why they have the properties that they possess. This work was funded through an EPSRC programme grant "Hard-soft materials: from understanding to engineering" and involved collaborations both within Sheffield, nationally and internationally. Further details can be found here.

A current project is using techniques and ideas developed during that grant to investigate environmentally benign methods of extracting rare earths (which are often critical minerals). Further details can be found using the link to the project SoS_RARE.

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 model experimental impedance data without the necessity of using over-simplified models of the grain boundary structure and equivalent circuits.

In all these projects, the group therefore uses 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

  • Crystallisation in the real world: Delivering control through theory and experiment
  • SoS RARE: Multidisciplinary research towards a secure and environmentally sustainable supply of critical rare earth elements (Nd and HREE) 
  • Modelling electroceramic materials, especially ferroelectrics and lithium battery cathode materials


Journal articles


Conference proceedings papers

  • Harding J, Freeman C, Finney A & Malini RI (2018) Understanding the mechanisms of biomineralisation: a grand challenge. ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, Vol. 255 View this article in WRRO RIS download Bibtex download
  • Williams CD, Travis KP, Harding JH & Burton NA (2015) Selective Ordering of Pertechnetate at the Interface between Amorphous Silica and Water: a Poisson Boltzmann Treatment. MRS Proceedings, Vol. 1744 (pp 53-58) RIS download Bibtex download
  • Rodger PM, Quigley D, Harding JH & Freeman CL (2010) Simulating crystal nucleation: Seeing the infrequent with Molecular dynamics. GEOCHIMICA ET COSMOCHIMICA ACTA, Vol. 74(12) (pp A875-A875) RIS download Bibtex download
  • Duffy DM, Freeman CL, Harding JH, Quigley D & Rodger PM (2009) Modelling biomineralization processes. GEOCHIMICA ET COSMOCHIMICA ACTA, Vol. 73(13) (pp A311-A311) RIS download Bibtex download
  • Freeman CL, Harding JH, Allan NL & Pinilla C (2009) Adsorption and segregation at surfaces in minerals and biominerals. GEOCHIMICA ET COSMOCHIMICA ACTA, Vol. 73(13) (pp A396-A396) RIS download Bibtex download
  • Yang MJ, Rodger PM, Harding JH & Stipp SLS (2009) Molecular dynamics simulations of peptides on calcite surface. MOLECULAR SIMULATION, Vol. 35(7) (pp 547-553) RIS download Bibtex download
  • Yang M, Harding J & Stipp SLS (2008) Simulations of monosaccharide on calcite surfaces. MINERALOGICAL MAGAZINE, Vol. 72(1) (pp 295-299) RIS download Bibtex download
  • Sloan J, Carter R, Vlandas A, Meyer RR, Liu Z, Suenaga K, Lindan PJD, Lin G, Harding J, Flahaut E , Giusca C et al (2008) Band-Gap Modification Induced in HgTe by Dimensional Constraint in Carbon Nanotubes: Effect of Nanotube Diameter on Microstructure. MICROSCOPY OF SEMICONDUCTING MATERIALS 2007, Vol. 120 (pp 213-+) RIS download Bibtex download
  • Sloan J, Carter R, Meyer RR, Vlandas A, Kirkland AI, Lindan PJD, Lin G, Harding J & Hutchison JL (2006) Structural correlation of band-gap modifications induced in mercury telluride by dimensional constraint in single walled carbon nanotubes. PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS, Vol. 243(13) (pp 3257-3262) RIS download Bibtex download
  • Freeman CL, Claeyssens F, Allan NL & Harding JH (2006) Thin films of wurtzite materials - AlN vs. AlP. JOURNAL OF CRYSTAL GROWTH, Vol. 294(1) (pp 111-117) RIS download Bibtex download
  • Lavrentiev MY, Allan NL, Harding JH, Harris DJ & Purton JA (2006) Atomistic simulations of surface diffusion and segregation in ceramics. COMPUTATIONAL MATERIALS SCIENCE, Vol. 36(1-2) (pp 54-59) RIS download Bibtex download
  • Harris DJ, Farrow TS, Harding JH, Lavrentiev MY, Allan NL, Smith W & Purton JA (2005) Surface diffusion and surface growth in nanofilms of mixed rocksalt oxides. PHYSICAL CHEMISTRY CHEMICAL PHYSICS, Vol. 7(8) (pp 1839-1844) RIS download Bibtex download
  • Venables JA & Harding JH (2000) Nucleation and growth of supported metal clusters at defect sites on oxide and halide (001) surfaces. JOURNAL OF CRYSTAL GROWTH, Vol. 211(1-4) (pp 27-33) RIS download Bibtex download
  • Harding JH & Harker AH (1998) Simulation of the Growth of Heterostructures. MRS Proceedings, Vol. 529 RIS download Bibtex download
  • Stoneham A (1998) Computer simulation of interfaces: what do we need to know?. Acta Materialia, Vol. 46(7) (pp 2255-2261) RIS download Bibtex download
  • Harding JH, Harris DJ & Parker SC (1997) Computer Simulation of Interfaces in Ceramics. MRS Proceedings, Vol. 492 RIS download Bibtex download
  • Carniato S, Boureau G & Harding J (1995) Simulation of oxygen vacancies at the Si-SiO2 interface. RADIATION EFFECTS AND DEFECTS IN SOLIDS, Vol. 134(1-4) (pp 179-183) RIS download Bibtex download
  • Cirolin S, Marchese M, Jacucci G, Harding JH & Mulheran PA (1994) Modelling the microstructure of thermal barrier coatings. American Society of Mechanical Engineers, Petroleum Division (Publication) PD, Vol. 62 (pp 189-198) RIS download Bibtex download
  • Ferrari M & Harding J (1990) Residual stress profile in plasma-sprayed ceramic coatings. American Society of Mechanical Engineers, Petroleum Division (Publication) PD, Vol. 32 (pp 197-202) RIS download Bibtex download
  • Holloway NJ, Vaughan GJ, Mignanelli M, Harding J & Potter PE (1986) PRIMARY CONTAINMENT SOURCE TERM ANALYSIS FOR CDFR - HYPOTHETICAL CORE DISRUPTIVE ACCIDENTS. (pp 103-108) RIS download Bibtex download


Teaching interests
  • MAT1610 Introduction to Materials Chemistry
  • MAT1410 Biomaterials I
  • MAT1920 Cradle to ? Materials and the Environment
  • MAT4600 Multiscale materials modelling
  • MAT6666 Materials selection, properties and applications
Professional activities
  • EPSRC Peer Review College
  • Organiser of the annual CCP5 International Summer School in Molecular Simulation 2008-13; lecturer 2004-present
  • External examiner, Foundation Year, University of Newcastle
  • Member of management committee, Materials Chemistry Consortium (ARCHER)
  • Member of N8 High Performance Computing steering committee