\n* work on [[C70 fullerene]]{{cite journal|last1=McKenzie|first1=D. R.|last2=Davis|first2=C. A.|last3=Cockayne|first3=D. J. H.|last4=Muller|first4=D. A.|last5=Vassallo|first5=A. M.|title=The structure of the C70 molecule|journal=Nature|volume=355|issue=6361|year=1992|pages=622–624|issn=0028-0836|doi=10.1038/355622a0|bibcode = 1992Natur.355..622M |s2cid=4265079}}}}"},"influences":{"wt":""},"influenced":{"wt":""},"awards":{"wt":"See list"},"spouse":{"wt":"Jean Kerr"},"children":{"wt":"Sophie,Tamsin and James"},"footnotes":{"wt":""}},"i":0}}]}" id="mwCQ">.mw-parser-output .infobox-subbox{padding:0;border:none;margin:-3px;width:auto;min-width:100%;font-size:100%;clear:none;float:none;background-color:transparent}.mw-parser-output .infobox-3cols-child{margin:auto}.mw-parser-output .infobox .navbar{font-size:100%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .infobox-full-data:not(.notheme)>div:not(.notheme)[style]{background:#1f1f23!important;color:#f8f9fa}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .infobox-full-data:not(.notheme) div:not(.notheme){background:#1f1f23!important;color:#f8f9fa}}@media(min-width:640px){body.skin--responsive .mw-parser-output .infobox-table{display:table!important}body.skin--responsive .mw-parser-output .infobox-table>caption{display:table-caption!important}body.skin--responsive .mw-parser-output .infobox-table>tbody{display:table-row-group}body.skin--responsive .mw-parser-output .infobox-table tr{display:table-row!important}body.skin--responsive .mw-parser-output .infobox-table th,body.skin--responsive .mw-parser-output .infobox-table td{padding-left:inherit;padding-right:inherit}}
David Cockayne | |
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Born | David John Hugh Cockayne 19 March 1942 |
Died | 22 December 2010 68) | (aged
Resting place | Oxford |
Alma mater |
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Known for |
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Spouse | Jean Kerr |
Children | Sophie, Tamsin and James |
Awards | See list |
Scientific career | |
Fields | Materials Science |
Thesis | Electron microscope images of defects in crystal lattices (1970) |
David John Hugh Cockayne FRS [5] FInstP (19 March 1942 – 22 December 2010) was Professor in the physical examination of materials in the Department of Materials at the University of Oxford and professorial fellow at Linacre College from 2000 to 2009. [6] [7] He was the president of the International Federation of Societies for Microscopy from 2003 till 2007, then vice-president 2007 to 2010. [5]
Cockayne was an electron microscopist who played an important role in the development of weak-beam transmission electron microscopy (TEM), and in the application of high resolution TEM to diamond, fullerenes and semiconductors. [8] [9] [10]
Cockayne was born in Balham, London, the second of three children of John Henry Cockayne, policeman and later staff manager, and his wife, Ivy, née Hatton. [11] In 1950, when he was 8, the family sailed from Tilbury on the Otranto, bound for Melbourne; [12] their new home was to be in the Geelong area of Victoria. In 1952 they moved to a newly-built house in Geelong, and Cockayne attended a new school, from where he was awarded a scholarship to Geelong Grammar School in 1953, where he excelled in chemistry, physics and mathematics.
In 1961 Cockayne enrolled at the University of Melbourne to read physics; he graduated in 1964 with first-class honours. He went on to do research on electron diffraction for an MSc, again gaining a first in 1966. [13] He was then awarded a Commonwealth Scholarship to read for a DPhil at Magdalen College, Oxford.
David joined the Department of Metallurgy in Oxford in September 1966 to conduct research on electron microscope images of defects in crystal lattices, under the supervision of Dr M J Whelan. He was awarded a DPhil in 1970. [14]
At the age of 32, Cockayne took up the post of director of the University of Sydney Electron Microscope Unit (EMU) in June 1974. He also held the position of associate professor. He was promoted to full professor in 1986, and then to a personal chair (Professor in Physics (Electron Microscopy and Microanalysis)) in 1992. He built up an important research base at Sydney; with David McKenzie he developed a high-precision electron diffraction technique within an electron microscope to study the structure of amorphous materials. [15]
Cockrayne moved back to Oxford in 2000, to take up the post of Professor in the Physical Examination of Materials, at the Department of Materials. He also became Professorial Fellow at Linacre College. In the department of materials he “built up an outstanding electron microscopy group”, and followed up studies started in Sydney on the properties of nanometer-sized crystals (quantum dots) insemiconductor alloys. [15]
“Cockayne was an inspirational lecturer and mentor. He cared deeply about research, teaching, and university administration, and brought lucidity and commitment in equal measure to all three.” […] His interests included “theatre, music, literature, photography, travel, and bushwalking”. [11] When he was an undergraduate at Trinity College, Melbourne University he met Jean Kerr, who enrolled a year after Cockrayne and was reading French and English honours. She was resident in the next-door hall, and they got to know each other early in 1962 and became close friends in 1964 [5] Shortly before he left for Oxford in September 1966, he proposed to Jean and they announced their engagement. She travelled to England in January 1967, and they were married in Shilton, Oxfordshire on 28 July 1967. The couple had three children: Sophie was born in Oxford in 1973; Tamsin in Sydney in 1975; and James in Sydney in 1977.
David Cockayne died from lung cancer on 22 December 2010. He was cremated in Oxford following a funeral service at the University Church of St Mary the Virgin on 5 January 2011. He wrote his own eulogy to give himself 'the pleasure of knowing what will have been said at my funeral'. [11]
When Cockayne was elected a Fellow of the Royal Society (FRS) in 1999 [5] his certificate of election noted that he was:
Distinguished for his contributions to the development of electron microscopy and its applications to Materials Science. He developed the theory, and with Ray the experimental procedures for the "weak beam" technique, which improved by an order of magnitude, to 1.5nm, the resolution at which complex lattice defect geometries could be studied. The technique has led to important advances in understanding of the structure and properties of defects, and is now a routine tool. Cockayne's papers in this field are classic. He applied the technique inter alia to measure accurate values of stacking fault energies, demonstrated unambiguously for the first time that dislocations in semiconductors are dissociated, whether stationary or gliding, and elucidated the structure and positions of misfit dislocations in strained layer superlattices. He has made important contributions to the interpretation of lattice fringes. Following earlier work by Grigson, with McKenzie he developed a powerful electron diffraction technique for determining radial distribution functions from small areas of amorphous materials, collecting only elastically scattered electrons, transforming the method into a precision tool giving nearest neighbour distances accurate to 0.01A. Applications include the demonstration of the existence of the amorphous form of tetrahedrally coordinated carbon, and the refinement of models for C60 and C70. Cockayne's work is remarkable for his deep physical insight, and his ability to apply this insight to the development of powerful and widely applicable techniques. [3]
Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is transmitted through a specimen to form an image. The specimen is most often an ultrathin section less than 100 nm thick or a suspension on a grid. An image is formed from the interaction of the electrons with the sample as the beam is transmitted through the specimen. The image is then magnified and focused onto an imaging device, such as a fluorescent screen, a layer of photographic film, or a detector such as a scintillator attached to a charge-coupled device or a direct electron detector.
Electron diffraction is a generic term for phenomena associated with changes in the direction of electron beams due to elastic interactions with atoms. It occurs due to elastic scattering, when there is no change in the energy of the electrons. The negatively charged electrons are scattered due to Coulomb forces when they interact with both the positively charged atomic core and the negatively charged electrons around the atoms. The resulting map of the directions of the electrons far from the sample is called a diffraction pattern, see for instance Figure 1. Beyond patterns showing the directions of electrons, electron diffraction also plays a major role in the contrast of images in electron microscopes.
Electron backscatter diffraction (EBSD) is a scanning electron microscopy (SEM) technique used to study the crystallographic structure of materials. EBSD is carried out in a scanning electron microscope equipped with an EBSD detector comprising at least a phosphorescent screen, a compact lens and a low-light camera. In the microscope an incident beam of electrons hits a tilted sample. As backscattered electrons leave the sample, they interact with the atoms and are both elastically diffracted and lose energy, leaving the sample at various scattering angles before reaching the phosphor screen forming Kikuchi patterns (EBSPs). The EBSD spatial resolution depends on many factors, including the nature of the material under study and the sample preparation. They can be indexed to provide information about the material's grain structure, grain orientation, and phase at the micro-scale. EBSD is used for impurities and defect studies, plastic deformation, and statistical analysis for average misorientation, grain size, and crystallographic texture. EBSD can also be combined with energy-dispersive X-ray spectroscopy (EDS), cathodoluminescence (CL), and wavelength-dispersive X-ray spectroscopy (WDS) for advanced phase identification and materials discovery.
A scanning transmission electron microscope (STEM) is a type of transmission electron microscope (TEM). Pronunciation is [stɛm] or [ɛsti:i:ɛm]. As with a conventional transmission electron microscope (CTEM), images are formed by electrons passing through a sufficiently thin specimen. However, unlike CTEM, in STEM the electron beam is focused to a fine spot which is then scanned over the sample in a raster illumination system constructed so that the sample is illuminated at each point with the beam parallel to the optical axis. The rastering of the beam across the sample makes STEM suitable for analytical techniques such as Z-contrast annular dark-field imaging, and spectroscopic mapping by energy dispersive X-ray (EDX) spectroscopy, or electron energy loss spectroscopy (EELS). These signals can be obtained simultaneously, allowing direct correlation of images and spectroscopic data.
The Department of Materials at the University of Oxford, England was founded in the 1950s as the Department of Metallurgy, by William Hume-Rothery, who was a reader in Oxford's Department of Inorganic Chemistry. It is part of the university's Mathematical, Physical and Life Sciences Division
Selected area (electron) diffraction is a crystallographic experimental technique typically performed using a transmission electron microscope (TEM). It is a specific case of electron diffraction used primarily in material science and solid state physics as one of the most common experimental techniques. Especially with appropriate analytical software, SAD patterns (SADP) can be used to determine crystal orientation, measure lattice constants or examine its defects.
Dark-field microscopy describes microscopy methods, in both light and electron microscopy, which exclude the unscattered beam from the image. Consequently, the field around the specimen is generally dark.
Ernst G. Bauer is a German-American physicist known for his studies in the field of surface science, thin film growth and nucleation mechanisms and the invention in 1962 of the Low Energy Electron Microscopy (LEEM). In the early 1990s, he extended the LEEM technique in two directions by developing Spin-Polarized Low Energy Electron Microscopy (SPLEEM) and Spectroscopic Photo Emission and Low Energy Electron Microscopy (SPELEEM). He is currently Distinguished Research Professor Emeritus at the Arizona State University.
Kikuchi lines are patterns of electrons formed by scattering. They pair up to form bands in electron diffraction from single crystal specimens, there to serve as "roads in orientation-space" for microscopists uncertain of what they are looking at. In transmission electron microscopes, they are easily seen in diffraction from regions of the specimen thick enough for multiple scattering. Unlike diffraction spots, which blink on and off as one tilts the crystal, Kikuchi bands mark orientation space with well-defined intersections as well as paths connecting one intersection to the next.
Michael John Whelan HonFRMS FRS FInstP is a British scientist.
George Andrew Davidson Briggs is a British scientist. He is Professor of Nanomaterials in the Department of Materials at the University of Oxford. He is best known for his early work in acoustic microscopy and his current work in materials for quantum technologies.
Paul Anthony Midgley FRS is a Professor of Materials Science in the Department of Materials Science and Metallurgy at the University of Cambridge and a fellow of Peterhouse, Cambridge.
John Charles Howorth Spence ForMemRS HonFRMS was Richard Snell Professor of Physics at Arizona State University and Director of Science at the National Science Foundation BioXFEL Science and Technology Center.
John Wickham Steeds is a British physicist and materials scientist. He is an Emeritus Professor of Physics at the University of Bristol.
Thomas Benjamin Britton is a materials scientist, engineer and Associate Professor at The University of British Columbia. His research interests are in micromechanics, deformation, strain and electron backscatter diffraction (EBSD). In 2014 he was awarded the Silver Medal of the Institute of Materials, Minerals and Mining (IOM3), a society of which he then became a Fellow in 2016.
Convergent beam electron diffraction (CBED) is an electron diffraction technique where a convergent or divergent beam of electrons is used to study materials.
Peter David Nellist, is a British physicist and materials scientist, currently a professor in the Department of Materials at the University of Oxford. He is noted for pioneering new techniques in high-resolution electron microscopy.
Angus J. Wilkinson is a professor of materials science based at the Department of Materials, University of Oxford. He is a specialist in micromechanics, electron microscopy and crystal plasticity. He assists in overseeing the MicroMechanics group while focusing on the fundamentals of material deformation. He developed the HR-EBSD method for mapping stress and dislocation density at high spatial resolution used at the micron scale in mechanical testing and micro-cantilevers to extract data on mechanical properties that are relevant to materials engineering.
Transmission Kikuchi Diffraction (TKD), also sometimes called transmission electron backscatter diffraction (t-EBSD), is a method for orientation mapping at the nanoscale. It’s used for analysing the microstructures of thin transmission electron microscopy (TEM) specimens in the scanning electron microscope (SEM). This technique has been widely utilised in the characterization of nano-crystalline materials, including oxides, superconductors, and metallic alloys.
Weak beam dark field (WBDF) microscopy is a type of transmission electron microscopy (TEM) dark field imaging technique that allows for the visualization of crystal defects with high resolution and contrast. Specifically, the technique is mainly used to study crystal defects such as dislocations, stacking faults, and interfaces in crystalline materials. WBDF is a valuable tool for studying the microstructure of materials, as it can provide detailed information about the nature and distribution of defects in crystals. These characteristics can have a significant impact on material properties such as strength, ductility, and corrosion resistance.