Sarah Haigh: Fast track to success
Image: Dr Sarah Haigh is breaking down barriers in academia and Materials Science. [University of Manchester]
In 2010 and only two years after completing her PhD, Dr Sarah Haigh took the position of Lecturer in Materials Characterisation at the University of Manchester, UK.
Having pioneered 'exit wave restoration' to boost resolution in TEM, the young materials scientist was, as she puts it: "ready to be thrown in the deep end."
"I was an unusually young lecturer, but I was enthusiastic," she highlights. "This jump from postdoctoral research to lecturer was a game-changer and was very hard work, but I would absolutely encourage anyone to go for it."
As a child, Haigh had been drawn towards the sciences and quantitative reasoning. With mathematician parents, she and her brother were encouraged to bring numbers into everyday play.
"One of my first memories is playing with my brother and timing cars as they rolled down a hill," she laughs. "I would confiscate the slow ones and he had to buy them back from me."
An interest in sciences continued throughout school and come her A' Levels, Haigh stumbled across Materials Science.
"I'd heard of an open day at Oxford University so asked my chemistry teacher, 'What's Materials Science?'" she says. "He said, 'I've no idea, go and find out'."
So she did, and thankful the discipline avoided the electrical circuit diagrams and organic chemistry formulae she loathed, opted for the subject.
"I had always liked the applications of the physical sciences and was told that Materials Science was a way to peek inside materials, understand how they work and make a difference to the world around me," she says.
So come the year 2000 and with A' Levels in hand, the young Haigh left home to study Materials Science at the University of Oxford. During her degree, Haigh was supported by The Armourers and Brasiers', a company that provides funds to metallurgy and material science undergraduates, and sponsored by Canada-based aluminium manufacturer, Alcan International, now known as Rio Tinto Alcan.
Each Summer was spent working at Alcan, in UK, providing Haigh with her first taste of industry so come the end of her degree, she was torn between pursuing a PhD or moving straight into the world of work.
As she says: "I'd been lucky to gain job offers from Alcan, as well as Rolls Royce, but talking to people I increasingly got the impression that I'd probably need a PhD if I wanted to work in industrial or academic research."
"And I figured it would be easier to do a PhD now, rather than after working for a few years and being used to earning money, so I signed up," she adds.
During her final year Masters project at the University of Oxford, Haigh had spent time using nanoscale secondary ion mass spectrometry - nanoSIMS - to investigate the chemical interactions in titanium-doped magnesium diboride superconducting bulk samples and wires.
At the time, the instrument was one of the first of its kind in the world, could map elements within complex nanostructured materials down to 50 nm resolution and Haigh had been hooked. However, a few doors down her corridor, researchers were busy installing a new transmission electron microscope.
"This TEM was one of the first in the world to have double aberration correction meaning it could take very good images in conventional TEM as well as in scanning TEM mode," she said. "I decided that for my PhD I wanted to use this even more expensive machine."
So come 2004, Haigh remained at the University of Oxford, and under the supervision of Professor Angus Kirkland, worked at developing 'Exit Wave Restoration' techniques. This method restores phase information from conventional high resolution TEM images and also eliminates residual aberrations.
"I was promoted to Reader last year and I'd like to see myself as a Professor within the next five to ten years"
Haigh published several papers on the method throughout her PhD, and as she highlights: "We got about a 40% improvement in resolution over what you would have in a single image which was great."
But for the young researcher, the wider impact of the final result was still disappointing. "The constraint here was that we had to work with fantastically thin samples to avoid problems with parallax, which limited the number of materials systems to which the approach was actually applicable," she explains.
Involved in industry
Throughout her PhD, Haigh had also been in contact with Japan-based electron microscope manufacturer, JEOL, heading out to Japan to test instruments prior to installation at Oxford.
Describing this time as an 'amazing cultural experience', she continued working with JEOL UK, post-PhD, as a consultant application specialist, sharing her time here and at Oxford University.
"It was difficult balancing working for a company and being in academia, but it was a superb opportunity," she says.
During the next two years, she spent a lot of time with the company in South Africa, including working with Professor Jan Neethling at the Centre for High Resolution Transmission Electron Microscopy, Nelson Mandela Metropolitan University. At the time, the Centre was heavily investing in new instruments and had bought the first aberration corrected electron microscope in South Africa from JEOL.
"I would be doing training courses, demonstrations and responding to microscopy tenders," she says. "And this has really benefited me now as an academic as you still have to sell your science, write bids and apply for money as well as working with industry."
But within a year of working with JEOL, Haigh had decided she also wanted her own microscope. As she puts it: "It was great training people to use their microscope but it was always frustrating to leave and not have any further input into helping them get results or to do research on that instrument."
Then came Manchester. Hearing about the position of Lecturer in Materials Characterisation at the University from a friend, Haigh realised this was an opportunity to get hold of her microscope. Plus, Manchester had many advantages.
"There were many people I could see myself working with, it's close to the SuperSTEM lab at Daresbury and while Manchester didn't have a really good TEM at the time, it did have the money to buy one," she says.
So come 2010, Haigh moved from Oxford to Manchester and within two weeks of starting had put out a tender for a TEM and subsequently bought an FEI Titan. According to the researcher, she wanted an instrument that was 'different to what anyone else had in the UK' and at the time, FEI could deliver a TEM, with a very large Energy Dispersive X-ray Spectroscopy (EDXS) detector, within budget.
"With this I knew you would be able to get elemental maps from X-rays at all tilt angles without having to tilt your sample towards the detector," she adds. "This meant I would be able to get a 3D reconstruction of an elemental distribution with the resolution of a nanometre-sized voxel."
And with instrument in hand, research has flourished. After her first year as a lecturer, Haigh recruited three PhD students, and now, six years on, has a team of five MSc students, six PhD students and 2.5 postdoctoral researchers.
A key strand of Haigh's research to date has been to develop electron tomography for the 3D elemental imaging of complex nanostructured materials, and during this time her team has produced incredibly high resolution 3D composition data on gold-silver nanoparticles. These nanoparticles are crucial to the catalytic performance of reactions to produce several important feedstock chemicals used worldwide.
"We started by looking at this beautiful system, which was a galvanically produced using gold salt and a silver seed particle, and this sort of 3D elemental mapping just would not have been possible without our EDX detector," she says.
At the same time, Haigh and colleagues have used the FEI Titan to probe chemical processes in fluids, marking the first time nanoscale composition changes have been observed directly in wet chemical processes. Here, they have simultaneously mapped the distribution of elements within silver nanowires, gold nanoparticles and more, while studying the evolution of nanostructures within liquid.
And in a different strand of research, Haigh has also been imaging novel 2D crystal heterostructure devices. As she explains: “You can’t be a microscopist in Manchester for long without getting interested in graphene; it is a very exciting and fast moving field."
Using cross-sectional TEM to take a look at graphene-boron nitride layered heterostructures, Haigh and colleagues had discovered that hydrocarbons trapped between these layers segregate into isolated pockets, leaving the interfaces atomically clean.
"What the microscopy showed here was very exciting," highlights Haigh. "If you know that your atoms are atomically matched or separated you can then decide on what bandstructure you want at the atomic scale, and hence build a bespoke device."
Cross-sectional STEM images and EELS elemental mapping of a tungsten disulphide quantum well LED structure [Haigh].
Indeed, Manchester University researchers have since fabricated transistors and novel light emitting diodes, based on this materials system, with Haigh imaging the structures.
So where next for the young researcher? She will continue to use EDX tomography to study new nanomaterials, and is also looking to apply in-situ elemental mapping to more materials systems.
As she says: "It's very rare that catalysts are used at room temperature and in an ultrahigh vacuum but these are the conditions which microscopists often use to look at their structure and try to understand their behavior. In-situ imaging allows us to overcome this limitation and perform analysis under more realistic environmental conditions".
And as she highlights, exploring new research avenues has always been important. "Keep trying new stuff; applying a technique in a new way or to a new material has lots of challenges but can produce great rewards."
But, her plans for academic success don't stop here.
"I was promoted to Reader last year and I'd like to see myself as a Professor within the next five to ten years," she says. "I'm beginning to believe I can cope with academia now; it gives you a lot of freedom to play, to travel, and teaching undergraduates, while working with my fantastic research students is just superb."