Tuesday 9 July 2013, Pentland Suite, 09:30-10:30
Plenary presentation
(plenary) Predicting and preventing failure: From test piece to operational plant
P J Withers
BP International Centre for Advanced Materials (BP-ICAM), The University of Manchester, UK
Understanding how, when and why things fail in service is both of academic and societal interest. In this lecture I
will show how the penetrating power of neutron beams can give us an inside view of how materials perform, often
under harsh conditions. I will look at how neutron diffraction can tell us about harmful residual stresses that may
add to the applied stresses to cause unexpected failure, or even cause failure on their own. Further I will show how
residual stresses can be engineered using smart materials or surface treatments to inhibit crack growth and prolong
safe lives. I will also show how SANS and neutron tomography can tell us about defects and how these can also
cause unexpected failure if not accounted for. Examples will be taken across the oil and gas, nuclear and aerospace
sectors where the highest levels of safety must be assured.
ICNS 2013 International Conference on Neutron Scattering
Wednesday 10 July 2013, Pentland Suite, 09:00-10:30
Plenary presentations
(plenary) A new role for diamond-anvil cells in extreme-conditions neutron science
H Mao1, M Guthrie1, R Boehler1, K Li1, S Machida1, J Molaison2, A dos Santos2 and C Tulk2
1
Geophysical Laboratory - Carnegie Institution of Washington, USA, 2Oak Ridge National Laboratory, USA
The development of diamond anvil cells (DACs) has driven a dramatic expansion of the extreme environment
science in recent decades and has generated broad impacts in basic physics and chemistry, geophysics and
planetary research and, increasingly, energy science. High-pressure neutron science, however, has been lagging
behind due to the double jeopardy of low neutron source intensity and the small DAC sample size. The construction
of new, intense neutron sources – such as the SNS at Oak Ridge National Laboratory - has promised a potential for
realizing a greatly increased role for DAC’s in neutrons diffraction at high-pressure. Here, I will outline the
importance of such a capability. I will present our implementation of newly designed, supported diamond anvils,
which have been optimized for neutron diffraction, at the SNS. These DACs have been demonstrated to reach
unprecedented pressures, with sample volume two orders of magnitude greater than previous devices. With
concurrent advances in both neutron and high-pressure technology over the coming decade, the rapid acceleration
of extreme-conditions neutron science is assured.
(plenary) Making maps of spin dynamics
T Perring
ISIS Facility, STFC Rutherford Appleton Laboratory, UK
The study of strongly correlated materials is a major theme in condensed matter physics because of the unexpected
physical properties and exotic phases that they can exhibit. Studies of the excitations in these systems can provide
the most sensitive tests of theory and shed light on the underlying processes responsible for the properties of
interest.
Over the past 15 years time-of-flight spectrometers have established themselves as extraordinarily effective
instruments for measuring excitations in single crystals where the interactions are strong in one or two dimensions,
for example in the cuprate superconductors and quasi one- and two-dimensional model magnetic systems.
However, until recently there have been relatively fewer experiments in systems where there are significant
interactions in all three spatial dimensions.
By combining a hundred or more separate runs with different crystal orientations into a single dataset, complete
measurements of the four dimensional scattering function S(qh,qk,ql,ω) can be made. This has become possible
through the combination of the latest instruments with large solid angle position sensitive detector arrays and –
crucially – optimized software to visualise and manipulate the massive data sets that are created.
In this talk I will review some examples of the insights that have come from mapping excitations, from quasi oneand two-dimensional systems using the well-established technique, and from three-dimensional systems using full
scattering function mapping. I will conclude with discussion of the current status and future prospects of the
technique.
ICNS 2013 International Conference on Neutron Scattering
Thursday 11 July 2013, Pentland Suite, 09:00-10:30
Plenary presentations
(plenary) Neutron studies on polymer thin films
T Kanaya
Kyoto University, Japan
Polymer thin films consisting of single component and multi components are of great interest because properties of
polymer thin films are very different from bulk, and directly related to many important phenomena such as coating,
adhesive, surface friction, lubricants, and dielectric layer. One of the most interesting findings in single component
polymer thin films is reduction in the glass transition temperature Tg. Recently, dewetting and phase separation of
polymer blend thin films are also of great interest from viewpoints of industrial applications as well as fundamental
investigations. The dewetting of the phase separated polymer blend thin film limits the industrial applications
because they require stable, homogeneous, and uniform thin films. This motivated the fundamental studies of
polymer blend thin films very much to reveal the dewetting mechanism and control the morphology for polymer
blend thin films.
In the presentation we will discuss these interesting but unusual properties of polymer thin films based on the
results of inelastic neutron scattering and specular and off-specular neutron reflectivity measurements.
(plenary) The role of neutron diffraction in understanding energy storage materials
L F Nazar
Department of Chemistry, Department of Physics and the Nanotechnology Institute, University of Waterloo, Canada
Significant advances in the energy density and rate capability of Li-ion batteries have been witnessed in the past
decade, with a wealth of new materials driving the research forward. Lithium metal phosphates saw their major
development start with olivine LiFePO4 in 1997. The fact that it has become a commercially viable electrode
material despite its essentially electronically insulating nature has continued to drive new directions amongst
researchers in this area. The combination of size control, functional conductive coatings, and variation in
composition and structure has resulted in many new related materials that may vie with LiFePO 4 for future
prominence. These include materials with the NASICON framework, and a new family of materials with the tavorite
structure. The latter contain fluorine as a network modifier, exemplified by transition metal (M) fluorophosphates
LiMPO4F and fluorosulfates LiMSO4F whose spacious channels are highly conducive to 3D Li-ion mobility. Some
demonstrate excellent electrochemical properties. Sulfates display a more favorable electrode potential than
phosphates owing to the larger “inductive effect, giving rise to higher energy density materials, and amongst these,
the disordered LiFeSO4F triplite modification exhibits a particularly high potential. Ion mobility in these frameworks
is strongly governed by subtle factors that relate to the depth of the “thermodynamic well” of the mobile ion, lattice
strain on ion extraction, and disorder of the mobile Li-ion on the transition metal sites. To understand these factors,
full knowledge of the structure is necessary, which is where neutron diffraction is essential. The fact that it can
detect light atoms such as Li even in the presence of heavy atoms, and can distinguish atoms with very similar mass
makes it an indispensable tool. This presentation will give an overview of the power of neutron diffraction in
structural characterization of a variety of energy storage materials, drawing on the examples cited above along with
others.
ICNS 2013 International Conference on Neutron Scattering
Friday 12 July 2013, Pentland Suite, 09:00-10:30
Plenary presentations
(plenary) Neutron scattering with computers
J C Smith
University of Tennessee, USA and Oak Ridge National Laboratory, USA
Integration with high-performance computer simulation [1] greatly increases the amount of information obtainable
from a typical neutron scattering experiment. We give examples of this approach in biophysical studies. Internal
protein motions are described in terms of three classes of motion [2], and surface hydration is shown to amplify
single-well protein atom diffusion in a manner propagating into the macromolecular core [3]. The elastic and
conformational softnesses of a protein are defined and quantified [4]. The derivation of generalised dynamical
fingerprints from simulation is discussed [5]. Spin-echo spectroscopy for the study of domain motions is described
[6], techniques for deriving mean-square displacements are examined [7] and the sequential effect on internal
motions of gradually heating a protein from 0 to 300K is described [8,9]. Functional dynamics in a drug processing
protein are determined [10]. Hydration effects on protein folding are probed [11,12]. Finally, physical processes
leading to the recalcitrance of biomass for cellulosic biofuel production are elucidated [13].
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
Lindner et al., Comp. Phys. Comm., 183(7), 1491-1501, (2012).
Hong et al., PRL, 107, 148102, (2011).
Hong et al., PRL, 108, 23 238102, (2012).
Hong et al., PRL, 110(2), 028104, (2013).
Noe et al., PNAS, 108(12), 4822-7, (2011).
Smolin et al., Biophys. J., 102(5), 1108-1117 (2012).
Zheng et al., JPCB, 116,1 6, 5028-5036 (2012).
Nickels et al., Biophys. J., 103(7), 1566-1575 (2012).
Miao et al., JACS, In press.
Miao et al., Biophys. J 103, 10, 2167-2176 (2012).
Godec et al., PRL, 107, 267801 (2011).
Daidone et al., Biophys J 103(7), 1518-1524, (2012).
Petridis et al., PRE, 83 (6-1) 061911 (2011).
(plenary) Emergence, stability and decay of skyrmions in chiral magnets
C Pfleiderer
Technische Universität München, Germany
Skyrmions are particle-like configurations of continuous fields named after the English particle physicist Tony
Skyrme. Their existence has long been considered in nuclear matter, quantum Hall systems, liquid crystals,
superfluid 3He and ultracold atoms. I will report on the emergence, stability and decay of skyrmions as a generic
property of chiral magnets, where they lead to an emergent electrodynamics with a wide range of practical
consequences. Namely, the non-zero topological winding corresponds to precisely one quantum of emergent
magnetic flux that mediates an extremely efficient coupling between the conduction electrons and the magnetic
properties. In turn, the emergent flux leads to a topological Hall signal, spin transfer torques at ultra-low current
densities and emergent electric fields. Additionally skyrmions are characterised by an exceptional stability, which
cannot be simply suppressed under large hydrostatic pressures. In fact, one important decay mechanism identified
recently are point defects, which may be viewed as quantized magnetic monopoles and antimonopoles, providing
sources and sinks of one flux quantum of emergent magnetic flux, respectively. This compares with measurements
ICNS 2013 International Conference on Neutron Scattering
of the Hall effect suggesting the survival of a topological winding akin that of skyrmions in the non-Fermi liquid
regime of MnSi at high pressures, where neutron scattering provides evidence of partial magnetic order without
quantum criticality.
ICNS 2013 International Conference on Neutron Scattering
Friday 12 July 2013, Pentland Suite, 16:00-16:45
AONSA Prize Session
Some Aspects of Neutron Scattering in India and Asia-Oceania Region: 1958 to 2012
B A Dasannacharya
Formerly Bhabha Atomic Research Centre, Mumbai and InterUniversity Consortium for DAE Facilities, India
Thermal Neutron scattering programme in India was initiated in 1958 at the Apsara reactor which was
commissioned in 1956. This moved over to Cirus, a 40MW natural uranium reactor with the maximum central flux of
6x1013 n/cm2/sec in the sixties. The next move happened in in late eighties to Dhruva which has a flux of 1.8x1014
n/cm2/sec. The growth of this programme was accompanied with innovative development of techniques and with
collaborations (a) in the South East Asian region, (b) with ISIS at Rutherford Appleton Laboratory, U.K. and (c) with
Indian Universities, at different times. The two aspects, namely, developments and collaborations were were
interdependent, to the benefit of science. I shall describe my involvement in this growth story starting from 1958,
when I joined the programme to now, highlighting the dependence of science and technology on each other.
ICNS 2013 International Conference on Neutron Scattering
Friday 12 July 2013, Pentland Suite, 16:45-17:30
Walter Hälg Prize Lecture
Neutrons and Life with a Pinch of Salt
G Zaccai
CNRS Grenoble, France
After a brief introduction on the early days of neutrons in biology [1], recent neutron scattering results will be
presented on adaptation of organisms that thrive in extreme conditions like the Dead
Sea.
[1]
G. Zaccai (2010): Neutrons and Biology: Three Decades of Excitement and More to Come, Neutron News,
21:1, 43-45
ICNS 2013 International Conference on Neutron Scattering