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Properties of ALD Al2O3 protective coatings
(American Vacuum Society, 2010-10-21) Evans, PJ; Murai, Y; Lindsay, MJ; Davis, J; Triani, G
In recent years, atomic layer deposition (ALD) has emerged as a technology platform for nanofabrication [1]. This interest has evolved from its intrinsic advantages; inherent thickness control, the ability to prepare highly conformal pin-hole free films, low temperature film growth and its large area uniformity. These redeeming characteristics have broadened the application of ALD films in such diverse areas as encapsulation of nanoparticles [2], templating of complex structures [3] and the modification of membranes [4]. The deposition of atomic layer protective coatings on flexible polymers and metals is another target application to improve the lifetime performance of functional materials that may be susceptible to degradation [5]. In particular, the ingress of moisture and atmospheric gases as well as the effects of abrasion and thermal cycling can significantly diminish a material’s suitability in cases where its bulk properties meet all other requirements. Inorganic barrier coatings on flexible substrates are subject to additional constraints where the mechanical strength and adhesion of the protective coating are particularly important. In this study, ALD alumina coatings were deposited on flexible substrates including polycarbonate, polyethylene naphthalate (PEN), copper and titanium, to investigate their toughness and adhesion under tensile load. In addition, the effect of deposition conditions on the performance of these protective coatings will be presented. References H. Kim, H.B.R. Lee, and W.J. Maeng, Thin Solid Films, 517 (2009) 2563-2580. J.R. Scheffe, A. Frances, D.M. King, X. Liang, B.A. Branch, A.S. Cavanagh, S.M. George, and A.W. Weimer, Thin Solid Films, 517 (2009) 1874-1879. G. Triani, P.J. Evans, D.J. Attard, K.E. Prince, J Bartlett, S. Tan, and R.P. Burford, J. Mater. Chem., 16 (2006) 1355-1359. L.Velleman, G. Triani, P.J. Evans, J. G. Shapter, and D. Losic, Micropor. Mesopor. Mater. 126 (2009) 87-94. T. Hirkikorpi, M. Vaha-Nissi, T. Mustonen, E.Iiskola and M. Karppinen, Thin Solid Films, 518 (2010) 2654-2658
Temperature dependence of diffuse scattering in PZN
(Springer Nature, 2011-08-12) Whitfield, RE; Studer, AJ; Goosens, DJ
Structural disorder seems to relate to the useful physical properties of ferroelectrics and relaxors. One such material is PZN, PbZn1/3Nb2/3O3. To explore what aspects of the disorder are specific to the polarized state, the temperature dependence of diffuse scattering in PZN has been investigated. The data were collected using both neutron and X-ray single crystal experiments in a range of temperatures from 50 K to 500 K (−223 °C to 227 °C). It has been found that some features, like the diffuse scattering from the B-site ordering, remain unchanged with change of temperature in terms of both intensity and peak shape. However, other diffuse scattering features evolve with T, for example the size effect scattering around the Bragg peaks. The size-effect becomes less pronounced with increasing temperature, with the diffuse scattering becoming more symmetric around the Bragg peaks. The diffuse rods caused by the planar domains change only slightly with temperature. This finding indicates that the planar domains persist into the paraelectric state but that the correlation between lead displacement and the average separation of adjacent lead atoms becomes weaker, suggesting that this size effect may be crucial to the ferroelectric properties. © 2011, The Minerals, Metals & Materials Society and ASM International
Crystal Structure of Protic Ionic Liquids and their hydrates
(International Union of Crystallography, 2021-08-14) Hassett, MP; Brand, HEA; Binns, J; Martin, AV; Greaves, TL
Protic Ionic Liquids (PILs) are a class of tailorable solvents made up of fused salts with melting points below 100 °C, which are formed through a Brønsted acid-base reaction involving proton exchange[1]. These solvents have applications as lubricants, electrolytes, and many other uses[2]. Although they are quite similar to molten salts, their crystal structures have not been explored in-depth, with only ethylammonium nitrate (EAN) having a reported crystal structure[3, 4]. Ten alkylammonium-based protic ionic liquids at both neat (<1 wt% water) and 90 mol% PIL, 10 mol% water concentrations were selected. Diffraction patterns were collected at the Australian Synchrotron ANSTO while attempting to crystallise the samples by cooling to 120 K. Five samples crystallised (3 neat, 2 dilute), where the temperature of the system was then increased at a rate of 6 K/min to room temperature. From these patterns we have identified a number of crystal phases, identifying their stability ranges and lattice constant variation from 120 K to room temperature. © 2021 The Authors
Data evaluation on the fly: Auto-Rickshaw at the MX beamlines of the Australian Synchrotron
(International Union of Crystallography, 2021-08-14) Panjikar, S
Auto-Rickshaw [1,2] is a system for automated crystal structure determination. It provides computer coded decision-makers for successive and automated execution of a number of existing macromolecular crystallographic computer programs thus forming a software pipeline for automated and efficient crystal structure determination. Auto-Rickshaw (AR) is freely accessible to the crystallography community through the EMBL-Hamburg AR Server [3]. Recently, it has been installed at the ASCI cluster at the Australian Synchrotron which uses Docker and Kubernetes system for launching AR jobs in high-throughput manner. The synchrotron AR server is accessible to users from the MX beamline computers. AR at the MX beamlines can be invoked through command line or a web-based graphical user interface (GUI) for data and parameter input and for monitoring the progress of structure determination. It can be also invoked via automatic data processing if the parameter inputs have been pre set at the AR-GUI during X-ray diffraction experiment. A large number of possible structure solution paths are encoded in the system and the optimal path is selected as the structure solution evolves. The platform can carry out experimental (SAD, SIRAS, RIP or various MAD) and MR phasing or combination of experimental and MR phasing. The system has extended extensively for evaluation of multiple datasets for various phasing protocols as well as for evaluation of ligand binding and fragment screening. The new implementation and features will be discussed during the presentation. © 2022 The Author
Towards real-time analysis of liquid jet alignment in SFX
(Australian Nuclear Science and Technology Organisation, 2021-11-25) Patel, J; Peele, AG; Abbey, B; Round, A; Mancuso, A
Serial femtosecond crystallography (SFX) enables atomic scale imaging of protein structures via X-ray diffraction measurements from large numbers of small crystals intersecting intense X-ray Free Electron Laser (XFEL) pulses. Sample injection typically involves continuous delivery of crystals to the pulsed XFEL beam via a liquid jet. Due to movement of the jet, which is often focused to further reduce its diameter using a gas virtual dynamic nozzle (GVDN), jet position is often adjusted multiple times during the experiment. This can result in loss of beamtime and significant manual intervention. Here we present a novel approach to the problem of liquid jet misalignment in SFX based on machine vision. We demonstrate automatic identification and classification of when there is overlap (‘hit’) and when there is not overlap (‘miss’) between the XFEL beam and jet. Our algorithm takes as its input optical images from the ‘side microscope’ located inside the X-ray hutch. This algorithm will be incorporated into the control system at the SFX/SPB beamline at the European XFEL where it will be used for in-situ ‘alignment correction’ via a continuous feedback loop with the stepper motors controlling the location of the nozzle within the chamber. Full automation of this process will result in a larger volume of useful data being collected. By increasing the efficiency and reducing the per experiment operational cost of SFX at the European XFEL a higher volume of experiments can be performed. In addition, via analysis of the feedback metrology we anticipate that optimised nozzle designs and jetting conditions could be achieved further benefitting the end user.

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