Research Profile - Department of Materials Science and Metallurgy ...

Paul Bristowe
Reader in Computational Materials Science
BSc University of East Anglia
PhD University of Surrey
+44 (0) 1223 334305
pdb1000@cam.ac.uk
www.msm.cam.ac.uk/asg/
Materials Modelling at the Atomic Level
Our research is concerned with the atomistic modelling of
defects, surfaces and interfaces in materials and their influence
on physical properties. We apply and develop modern quantummechanical
methods and focus on functional materials with
electronic and optical applications.
Multilayer optical coatings
Multilayer thin-film coatings are widely used in many optical
applications including UV and infra-red blockers, lighting filters,
anti-reflective films on spectacle lenses, solar control films on
windows and conductive films on flat-screen displays. The
interfaces between the multilayers of the coatings have an
important influence not only on the optical properties of the
films but also on their mechanical properties. We are using
quantum-mechanical density-functional calculations to predict
the structure, energy, bonding and dielectric characteristics of
various metal/oxide interfaces in these systems with the aim of
developing coatings with improved properties.
Ferroelectric materials for memory devices
Ferroelectric memory (FRAM) is a leading alternative technology
to silicon flash memory because it is non-volatile, has a short
erase time and operates at low voltages. Standard ferroelectric
materials for FRAM are the perovskite-type compounds PZT and
SBT. To further improve their ferroelectric properties, additional
chemical substitutions have been made resulting in complex
solid solutions such as PZTN, PLZT and BLT. We are using
density-functional methods to predict the structural, chemical
and electronic properties of these ferroelectrics in their bulk and
thin-film form, focusing on defects, surfaces and interfaces.
Fast ion conductors
Interest in zirconia-based solid electrolytes for fuel-cell and
sensor applications has lead to many atomic-scale simulations
of these materials aimed at deducing the ionic diffusion
mechanisms and relating them to the measured variation in
conductivity. We are extending these simulations to consider
more complex chemistries and microstructures including grain
boundaries with the goal of predicting new materials with
enhanced ionic conductivity.
ZS Lin & PD Bristowe, “Microscopic characteristics of the Ag(111)/
ZnO(0001) interface present in optical coatings” Phys. Rev. B 75, 205423
(2007).
H Chappell, M Duer, N Groom, C Pickard & PD Bristowe, “Probing the
surface structure of hydroxyapatite using NMR spectroscopy and first
principles calculations” Phys. Chem. Chem. Phys. 10, 600–606 (2008).
ZS Lin & PD Bristowe, “A density functional study of the effect of hydrogen
on the strength of an epitaxial Ag/ZnO interface” J. Appl. Phys. 102,
103513 (2007).
SH Shah, PD Bristowe, AM Kolpak & AM Rappe, “First principles study
of three-component SrTiO 3
/BaTiO 3
/PbTiO 3
ferroelectric superlattices” J.
Mater. Sci. 43, 3750-3760 (2008).
A small cluster of Ag atoms (grey) adsorbed onto a ZnO (0001)
surface
10 Research Profile