Patrick: Influence and Inspiration
Rob Jackson
Lennard-Jones Laboratories
School of Physical & Geographical Sciences
Keele University
Keele, Staffordshire ST5 5BG, UK
http://www.robajackson.com
Advances in the Chemistry of Disordered
Solids: UCL 13/09/2013
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Plan of talk
• Influence
– conferences and meetings
– textbooks
• Inspiration
– My research and Patrick’s influence on it
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EURODIM/ICDIM Conferences
• Patrick was very influential as a member of the
international advisory committee of the
EURODIM/LATDIC/ICDIM series of conferences.
• He was at the first one I attended, in Dublin
(1982), and the last one he attended was the
one I organised at Keele in 1998 (as well as most
of those in between).
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Organising committee for
‘LATDIC82’ (photo: UCD 1981)
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ICDIM1988 & EURODIM98
Parma & Keele
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London (Ontario): ‘Retirement’ Symposium: 15-16 Sept. 1989
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Solids: UCL 13/09/2013
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UWO symposium programme – morning
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Solids: UCL 13/09/2013
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UWO symposium programme – afternoon
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Solids: UCL 13/09/2013
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Photos from London (Ontario)
September 1989
Four wise gentlemen
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Photos from London (Ontario)
September 1989
With Roger Baetzold,
Richard C & Yen Tan
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Photos from London (Ontario)
September 1989
With Yen Tan & Sean Corish
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Photos from London (Ontario)
September 1989
Alastair Cormack
snaps away
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Photos from London (Ontario)
September 1989
With Bill Meath
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Mansfield College meetings
Patrick regularly
attended
the Mansfield College
meetings, organised by
Richard Catlow,
including this one, in
1988. Who else can you
recognise in the photo?
A later meeting was
organised to mark his
retirement, but I don’t
have a photo for that!
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Influence: Keele
• Although I first met Patrick when I was a postdoc
at UCL in the early 1980s, it was really at Keele
in 1986 when I first worked with him. He visited
Keele from 17 August for 2 weeks, with Sean,
Roger Baetzold and Yen Tan; the visit which
famously included the Bank Holiday weekend,
terrible weather, and the ‘second worst day’ of
Patrick’s life ...
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Keele: August 1986
• In 1986 the development of photographic film
was still a topic of commercial importance, and
Patrick, Sean, Roger and Yen were trying to
improve the existing potentials for the silver
halides.
• My small part in this story was showing Patrick
how to use CASCADE (based on HADES, and
which preceded GULP).
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Silver halides modelling
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Solids: UCL 13/09/2013
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The paper itself …
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Solids: UCL 13/09/2013
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Influence: Textbooks
• Since retirement, Patrick has written two
textbooks:
‘Group Theory with Applications
in Chemical Physics’ (2005)
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‘Thermodynamics’ (May 2013)
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Research inspiration
• Advice offered by PWMJ:
– (Your research plan) must be realistic, but
should bring out the fact that you have plenty
of ideas and will be able to develop an active
research programme which will involve not
only yourself but future graduate students.
– This was very useful to me as I began my
career, and I have tried to continue to follow it
ever since.
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My recent research
• We are interested in using computer modelling
to assist in the understanding, design and
optimisation of new materials for specific
applications.
• Applications of current interest are in optical
devices, and materials relevant to nuclear
energy generation.
• I will focus on four areas.
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1. Modelling nuclear fuels
• My original postdoc contract at UCL was to
model fission gases in UO2. This culminated in a
publication in 1986 which reported a new
potential for this material.
• As a result of the renewed interest in nuclear
energy, and a research collaboration with Mark
Read, it seemed appropriate to revisit the
modelling of UO2 and other actinide oxides:
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Journal of Nuclear Materials 406,
293-303 (2010)
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How good is the final fit?
(More details in paper)
Parameter
Calc.
Obs.
D%
Parameter
Calc.
Obs.
D%
Lattice Constant
[Å]
5.4682
5.4682
0.0
C11 [GPa]
391.4
389.3
0.5
U4+ – U4+
Separation [Å]
3.8666
3.8666
0.0
C12 [GPa]
116.7
118.7
-1.7
U4+ – O2Separation [Å]
2.3678
2.3678
0.0
C44 [GPa]
58.1
59.7
-2.7
O2- – O2Separation [Å]
2.7341
2.7341
0.0
Bulk Modulus [GPa]
208.3
204.0
2.1
Static Dielectric
Constant
24.8
24.0
3.3
High Frequency
Dielectric Constant
5.0
5.3
-5.7
Note that it is unusual to have this amount of data to fit to!
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Latest work on nuclear fuels
• The potential has been used to calculate the
defect properties of UO2
• A similar procedure has been applied to PuO2
and mixed oxide (MOX) fuel has been modelled
(funded through a PhD studentship from AWE).
• The next slide shows some recent work from
Scott Walker.
• On an interesting note, most other current work
on UO2 is being done using DFT!
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Modelling MOX fuel
The MOX system UO2/PuO2 was modelled for a range of Pu
concentrations allowing the variation of lattice parameter with
Pu concentration to be predicted. As expected, lattice parameter
decreases linearly with increasing Pu concentration.
From: S R Walker, PhD thesis
(in preparation)
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2. Modelling materials for
nuclear clock applications
•
229Th
is being investigated for use in ‘nuclear
clocks’; its first nuclear excited state is only ~ 8 eV
above the ground state, and can be probed by VUV
radiation.
• Nuclear clocks promise up to 6 orders of magnitude
improvement in precision over next generation
atomic clocks, as well as enhanced stability.
• Th has to be doped into a suitable crystal: CaF2 and
LiCaAlF6/LiSrAlF6 are being tested.
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Journal of Physics: Condensed
Matter 21, 325403 (2009)
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Summary of nuclear clocks
project
• In all 3 materials the Th4+ ion is predicted to
dope at the 2+ site (Ca2+ or Sr2+) with charge
compensation by formation of F- interstitials.
• DFT calculations have been carried out which
show that the presence of the defects does not
affect the band gap of the material.
• Crystals are being grown (using the cheaper 232
isotope initially).
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Green because of the colour
of the laser pointer!
232Th
doped CaF2
http://www.thorium.at/?p=481
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Other active areas
• 3. Modelling of optical materials
– Here mixed metal fluorides are modelled, doped
with rare earths, to determine the dopant
location and effect on crystal morphology.
• 4. Modelling of lithium niobate
– We revisited this material (following the
Donnerberg work in the 1980s) and derived a
new potential. LiNbO3 is still of interest
(conference in Germany next week!)
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Some of those who couldn’t attend but sent
messages/apologies
• John Vail (letter on next
slide)
• Roger Baetzold (‘will be
there in spirit’)
• Darrell Comins
• David Smith
• Bud Bridges
• Miguel Moreno
• Wyn Roberts
• Peter Sushko
• Martin Nikl
• Mário Valerio
• Bill Meath
• Neil Allan
• Alan Lidiard
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“Dear Rob,
Thanks for the notice of the Patrick Jacobs memorial symposium. Although I am in
reasonably good health and able to continue with research, my medical condition is
not sufficiently stable to get health insurance for a trip abroad. Please convey the
following message to our mutual colleagues who attend.
I met Patrick Jacobs through our mutual involvement with Theoretical Physics
Division at Harwell. It was immediately evident that he was truly “a scholar and a
gentleman.” We in Canada were fortunate to have shared his second career in
London, Ontario. I was well aware of his first career in London, England. To my
knowledge, his contributions to the understanding of atomic diffusion and optical
properties of solids and their defects were particularly notable. I was fortunate to
attend his retirement symposium at the University of Western Ontario. I was also
present in Riga when his wife Rita suffered a stroke that led to her death. It was sad
beyond my ability to describe. I wish that I could be with our many friends on this
occasion to renew our contacts and to celebrate Patrick’s memory. I send particular
greeting to Richard Catlow, Sean Corish, Eugene Kotomin and yourself, Rob Jackson.
There will no doubt be others there whose acquaintance I equally cherish. Some of
you may be interested to know that I continue with the Harwell legacy in Canada by
my research: “Electron density waves having the grapheme structure.”
All Hail, John Vail.”
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Conclusions
• Patrick had a considerable impact on my career.
His interest in my work and friendly advice was
always appreciated.
• I hope the special journal issue being planned is
a fitting tribute to his many contributions to our
field.
• Thanks for attending, and I hope you are
enjoying the symposium.
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