I07-Surface & interface diffraction
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A.
Wilson
,
I. M.
Nadeem
,
H.
Hussain
,
X.
Torrelles
,
J.
Imran
,
D.
Garai
,
R.
Lindsay
,
G.
Cabailh
,
J.
Zegenhagen
,
G.
Thornton
,
C.
Nicklin
Open Access
Abstract: A Photo-ElectroChemical DrOplet Cell (PEC-DOC) has been developed for the I07 surface diffraction beamline of Diamond Light Source to investigate solid-liquid interfaces using Surface X-Ray Diffraction (SXRD). PEC-DOC is ultrahigh vacuum (UHV) compatible, and so can be directly attached to a UHV instrument, such as that available in the Surface and Interface Laboratory at Diamond Light Source. Hence, samples can be prepared using standard surface preparation methods, such as sputtering/annealing, and then be characterised using X-ray photoemission spectroscopy (XPS) and scanning tunnelling microscopy (STM). Subsequently, a sample can be transferred in UHV in PEC-DOC to I07, where the structure of the solid-liquid interface can be investigated.
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May 2025
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I07-Surface & interface diffraction
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Immad
Nadeem
,
Christopher
Penschke
,
Ji
Chen
,
Xavier
Torrelles
,
Axel
Wilson
,
Hadeel
Hussain
,
Gregory
Cabailh
,
Oier
Bikondoa
,
Jameel
Imran
,
Christopher
Nicklin
,
Robert
Lindsay
,
Jorg
Zegenhagen
,
Matthew O.
Blunt
,
Angelos
Michaelides
,
Geoff
Thornton
Diamond Proposal Number(s):
[11345, 26045]
Open Access
Abstract: Metal-oxide aqueous interfaces are important in areas as varied as photocatalysis and mineral reforming. Crucial to the chemistry at these interfaces is the structure of the electrical double layer formed when anions or cations compensate for the charge arising from adsorbed H+ or OH–. This has proven extremely challenging to determine at the atomic level. In this work, we use a surface science approach, involving atomic level characterization, to determine the structure of pH-dependent model electrified interfaces of TiO2(110) with HCl and NaOH using surface X-ray diffraction (SXRD). A comparison with ab initio molecular dynamics calculations reveals the formation of surprisingly compact double layers. These involve inner-sphere bound Cl and Na ions, with respectively H+ and O–/OH– in the contact layer. Their exceptionally high electric fields will play a key role in determining the chemical reactivity.
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Nov 2024
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James C
Blakesley
,
Ruy Sebastian
Bonilla
,
Marina
Freitag
,
Alex
Ganose
,
Nicola
Gasparini
,
Pascal
Kaienburg
,
George
Koutsourakis
,
Jonathan D.
Major
,
Jenny
Nelson
,
Nakita K.
Noel
,
Bart
Roose
,
Jae Sung
Yun
,
Simon
Aliwell
,
Pietro
Altermatt
,
Tayebeh
Ameri
,
Virgil
Andrei
,
Ardalan
Armin
,
Diego
Bagnis
,
Jenny
Baker
,
Hamish
Beath
,
Mathieu
Bellanger
,
Philippe
Berrouard
,
Jochen
Blumberger
,
Stuart
Boden
,
Hugo
Bronstein
,
Matthew J.
Carnie
,
Chris
Case
,
Fernando A.
Castro
,
Yi-Ming
Chang
,
Elmer
Chao
,
Tracey M.
Clarke
,
Graeme
Cooke
,
Pablo
Docampo
,
Ken
Durose
,
James
Durrant
,
Marina
Filip
,
Richard H.
Friend
,
Jarvist M.
Frost
,
Elizabeth
Gibson
,
Alexander J.
Gillett
,
Pooja
Goddard
,
Severin
Habisreutinger
,
Martin
Heeney
,
Arthur D.
Hendsbee
,
Louise C.
Hirst
,
Saiful
Islam
,
Imalka
Jayawardena
,
Michael
Johnston
,
Matthias
Kauer
,
Jeff
Kettle
,
Ji-Seon
Kim
,
Dan
Lamb
,
David G.
Lidzey
,
Jihoo
Lim
,
Roderick
Mackenzie
,
Nigel
Mason
,
Iain
Mcculloch
,
Keith
Mckenna
,
Sebastian
Meier
,
Paul
Meredith
,
Graham
Morse
,
John
Murphy
,
Chris
Nicklin
,
Paloma
Ortega-Arriaga
,
Thomas
Osterberg
,
Jay
Patel
,
Anthony
Peaker
,
Moritz
Riede
,
Martyn
Rush
,
James
Ryan
,
David O.
Scanlon
,
Peter
Skabara
,
Franky
So
,
Henry J.
Snaith
,
Ludmilla
Steier
,
Jarla
Thiesbrummel
,
Alessandro
Troisi
,
Craig
Underwood
,
Karsten
Walzer
,
Trystan M.
Watson
,
Michael
Walls
,
Aron
Walsh
,
Lucy D.
Whalley
,
Benedict
Winchester
,
Sam
Stranks
,
Robert
Hoye
Open Access
Abstract: Photovoltaics (PVs) are a critical technology for curbing growing levels of anthropogenic greenhouse gas emissions, and meeting increases in future demand for low-carbon electricity. In order to fulfil ambitions for net-zero carbon dioxide equivalent (CO2eq) emissions worldwide, the global cumulative capacity of solar PVs must increase by an order of magnitude from 0.9 TWp in 2021 to 8.5 TWp by 2050 according to the International Renewable Energy Agency, which is considered to be a highly conservative estimate. In 2020, the Henry Royce Institute brought together the UK PV community to discuss the critical technological and infrastructure challenges that need to be overcome to address the vast challenges in accelerating PV deployment. Herein, we examine the key developments in the global community, especially the progress made in the field since this earlier roadmap, bringing together experts primarily from the UK across the breadth of the photovoltaics community. The focus is both on the challenges in improving the efficiency, stability and levelized cost of electricity of current technologies for utility-scale PVs, as well as the fundamental questions in novel technologies that can have a significant impact on emerging markets, such as indoor PVs, space PVs, and agrivoltaics. We discuss challenges in advanced metrology and computational tools, as well as the growing synergies between PVs and solar fuels, and offer a perspective on the environmental sustainability of the PV industry. Through this roadmap, we emphasize promising pathways forward in both the short- and long-term, and for communities working on technologies across a range of maturity levels to learn from each other.
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Aug 2024
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I07-Surface & interface diffraction
I09-Surface and Interface Structural Analysis
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Diamond Proposal Number(s):
[31429, 33153]
Open Access
Abstract: A structure determination of the commensurate phase formed by 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (F4TCNQ) absorbed on Ag(111) is reported. Initial characterization was performed using low-energy electron diffraction and synchrotron radiation photoelectron spectroscopy, with quantitative structural data being provided by normal incident X-ray standing waves (NIXSW) and surface X-ray diffraction (SXRD). NIXSW data show the F4TCNQ molecule to adopt a “twisted” conformation on the surface, previously found to be associated with metal adatom incorporation into a 2d-metal–organic framework for F4TCNQ on Au(111), Ag(100), and Cu(111). SXRD results provide direct evidence of the presence of Ag adatoms that are found to occupy near-bridge or fcc hollow sites with respect to the underlying surface, at an adsorption height of 2.69 ± 0.10 Å. The results show a consistent pattern of behavior for F4TCNQ adsorption on the (111) surfaces of Cu, Ag, and Au.
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Jul 2024
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Gianluigi A.
Botton
,
Peter
Coll
,
Andrew J.
Dent
,
Sarnjeet
Dhesi
,
Sky
French
,
David R.
Hall
,
Joseph
Hriljac
,
Sarah
Macdonell
,
Sofia
Diaz-Moreno
,
Chris
Nicklin
,
Paul
Quinn
,
Robert
Rambo
,
Kawal
Sawhney
,
Richard P.
Walker
,
Martin A.
Walsh
,
Molly
Pekarik-Fry
Open Access
Abstract: A look at the Diamond-II upgrade programme
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Mar 2024
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I07-Surface & interface diffraction
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Diamond Proposal Number(s):
[11597]
Open Access
Abstract: Development of next-generation electrochemical devices, such as solid oxide cells, requires control of the charge transfer processes across key interfaces. Structural strain at electrolyte:electrode interfaces could potentially alter the devices’ charge transport properties, therefore understanding the structural behavior of electrode surfaces under operating conditions is important. The functional oxide single crystal substrate SrLaAlO4 has been well-characterized with bulk structure studies; however, there are very few studies of SrLaAlO4 surface structures. Here, we present an investigation of the surface structure of SrLaAlO4 (001) substrates using surface x-ray diffraction under UHV conditions (10−10 Torr) with the substrate held at either room temperature or 650 °C. Best-fit models using a 1:1 ratio of Sr:La showed significant distortions to the surface AlO6 octahedra.
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Nov 2023
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I07-Surface & interface diffraction
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Diamond Proposal Number(s):
[24284]
Open Access
Abstract: A previous investigation of the structure of TCNQ adsorbed on Ag(111) using normal-incidence X-ray standing waves (NIXSW) and density functional theory (DFT) provided indirect evidence that Ag adatoms must be incorporated into the molecular overlayer. New surface X-ray diffraction (SXRD) results, presented here, provide direct evidence for the presence and location of these Ag adatoms and clearly distinguishes between two alternative models of the adatom registry favored by two different DFT studies.
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Feb 2023
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I07-Surface & interface diffraction
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Alexandra L.
Martin
,
Philip N.
Jemmett
,
Thomas
Howitt
,
Mary H.
Wood
,
Andrew W.
Burley
,
Liam R.
Cox
,
Timothy R.
Dafforn
,
Rebecca J. L.
Welbourn
,
Mario
Campana
,
Maximilian W. A.
Skoda
,
Joseph J.
Thompson
,
Hadeel
Hussain
,
Jonathan L.
Rawle
,
Francesco
Carla
,
Christopher L.
Nicklin
,
Thomas
Arnold
,
Sarah L.
Horswell
Diamond Proposal Number(s):
[14670, 16423, 19542]
Open Access
Abstract: The effect of lipid composition on models of the inner leaflet of mammalian cell membranes has been investigated. Grazing incidence X-ray diffraction and X-ray and neutron reflectivity have been used to characterize lipid packing and solvation, while electrochemical and infrared spectroscopic methods have been employed to probe phase behavior in an applied electric field. Introducing a small quantity of the anionic lipid dimyristoylphosphatidylserine (DMPS) into bilayers of zwitterionic dimyristoylphosphatidylethanolamine (DMPE) results in a significant change in the bilayer response to an applied field: the tilt of the hydrocarbon chains increases before returning to the original tilt angle on detachment of the bilayer. Equimolar mixtures, with slightly closer chain packing, exhibit a similar but weaker response. The latter also tend to incorporate more solvent during this electrochemical phase transition, at levels similar to those of pure DMPS. Reflectivity measurements reveal greater solvation of lipid layers for DMPS > 30 mol %, matching the greater propensity for DMPS-rich bilayers to incorporate water. Taken together, the data indicate that the range of 10–35 mol % DMPS provides optimum bilayer properties (in flexibility and function as a barrier), which may explain why the DMPS content of cell membranes tends to be found within this range.
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Feb 2023
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Optics
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Open Access
Abstract: Angle-resolved photoemission spectroscopy (ARPES) is a powerful method for measuring the electronic band structure of solids. Diamond Light Source is planning to build a multibend-achromat (MBA) synchrotron – Diamond-II - which will provide an almost diffraction-limited photon source in the vacuum-ultraviolet photon energy range. The improved emittance and higher coherence of MBA synchrotrons means that samples with features smaller than 1 µm can be readily studied using ARPES, provided the beamline is designed to take full advantage of the new photon source. We have developed an analytical method for optimising the optical design of a future Nano-ARPES beamline for Diamond-II. Our method enables one to explore large regions of parameter space for a beamline design in an unbiased and systematic way, with minimal requirements on computing power. We believe that the analytical method presented here will be a useful tool for synchrotron beamline designers, as it allows many beamline characteristics to be simulated quickly while working within any practical limitations.
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Dec 2022
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I07-Surface & interface diffraction
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Philip N.
Jemmett
,
David C.
Milan
,
Richard J.
Nichols
,
Thomas
Howitt
,
Alexandra L.
Martin
,
Thomas
Arnold
,
Jonathan L.
Rawle
,
Christopher L.
Nicklin
,
Timothy R.
Dafforn
,
Liam R.
Cox
,
Sarah L.
Horswell
Diamond Proposal Number(s):
[15539, 18202]
Open Access
Abstract: Sphingolipids are an important class of lipids found in mammalian cell membranes with important structural and signaling roles. They differ from another major group of lipids, the glycerophospholipids, in the connection of their hydrocarbon chains to their headgroups. In this study, a combination of electrochemical and structural methods has been used to elucidate the effect of this difference on sphingolipid behavior in an applied electric field. N-Palmitoyl sphingomyelin forms bilayers of similar coverage and thickness to its close analogue di-palmitoyl phosphatidylcholine. Grazing incidence diffraction data show slightly closer packing and a smaller chain tilt angle from the surface normal. Electrochemical IR results at low charge density show that the difference in tilt angle is retained on deposition to form bilayers. The bilayers respond differently to increasing electric field strength: chain tilt angles increase for both molecules, but sphingomyelin chains remain tilted as field strength is further increased. This behavior is correlated with disruption of the hydrogen-bonding network of small groups of sphingomyelin molecules, which may have significance for the behavior of molecules in lipid rafts in the presence of strong fields induced by ion gradients or asymmetric distribution of charged lipids.
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Nov 2022
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