Stanford Report, November 9, 2012
Marshall, who arrived at Stanford in 1979, has dedicated her career to training others and to enhancing the excellence of materials characterization at the university.
By Kathleen J. Sullivan L.A. Cicero
O'Neill Award winner Ann Marshall
An expert at both the theory and practice of electron microscopy. An outstanding woman scientist who has mentored, nurtured and trained generations of graduate students. A talented and dedicated professional who runs an outstanding research enterprise.
Those are some of the many accolades bestowed upon Ann F. Marshall, winner of the 2012 Marshall D. O'Neill Award, which honors staff members who have made outstanding contributions to Stanford's research mission.
Marshall will be honored Nov. 12 at a 4 p.m. reception at the Faculty Club.
Marshall is a senior research scientist in the Stanford Nanocharacterization Laboratory and the Stanford Nano Center, where she helps oversee the electron and ion microscopy facilities, including the transmission electron microscopes, the scanning electron microscopes and the focused ion beam instruments.
She trains students and postdoctoral researchers about how the instruments work and how to obtain and analyze the most valuable and reproducible data. She has collaborated on many research projects with faculty and students over the years.
Marshall, who arrived at Stanford in 1979, also has worked at the Center for Materials Research, the Superconductivity Interdisciplinary Research Group and the Geballe Laboratory for Advanced Materials.
Since 1980, Marshall has taught a yearly laboratory course on transmission electron microscopy techniques in the Department of Materials Science and Engineering (MSE).
Marshall grew up in a small town in Maryland and comes from a big family – she has nine siblings – but she was the only one who became a scientist.
"My family is full of English literature majors, and my dad was a professor of Greek and Latin," she said. "I first started thinking 'I like science' when I took chemistry in high school," she said in a recent interview.
Marshall earned a bachelor's degree in chemistry from Catholic University in Washington, D.C., in 1971. After graduating, she got a job as a technician in the university's materials science laboratory. That's where she discovered what she really liked – materials science. Graduate students working in the lab – they were friends – encouraged her to go back to school. She graduated with a doctorate in materials science and engineering from the University of Virginia in 1979.
"When I started studying materials science I realized how much structure there is at the microscopic and nano scale to all these things around us – metals, ceramics, plastics, and organic and biological materials," she said. "With an electron microscope you can see these microstructures much better than with a light microscope, and in many different ways. It's a visual world. It's really a lot of fun."
Marshall said she found out she'd won the O'Neill Award when she was in Oregon at a workshop and received a call from Ann Arvin, dean of research at Stanford.
"I had no idea I'd been nominated or that various colleagues had gone to all this trouble to write letters nominating me," Marshall said. "I'm very honored."
Robert Sinclair, a professor of materials science and engineering, and director of the Stanford Nanocharacterization Laboratory, described Marshall as an "expert at both the theory and practice of electron microscopy, a rigorous and complicated field in its own right, with many national and international conferences each year."
Sinclair said Marshall's style has been to train students and postdocs on how the electron microscope works, and how to go about obtaining and analyzing the most valuable and reproducible data.
"Ann clearly runs an outstanding research enterprise," Sinclair wrote in a letter nominating Marshall for the award.
"I have visited many electron microscope facilities throughout my career, and so often one sees that the professional staff acts as a barrier to the full use of the delicate TEM [transmission electron microscope] equipment. Ann has the opposite philosophy. By sincerely encouraging student hands-on usage of the facility, she is able to inculcate a respect for the laboratory so that accidental damage is a very rare occurrence.
"Indeed, several of my former students have been inspired to take on equivalent positions at other institutions and have adopted her way of working with students. 'I want to be the Ann Marshall of the East Coast' was what one of my graduating PhDs remarked."
Every year, Marshall teaches 12 students in a highly rigorous laboratory course for MSE titled Transmission Electron Microscopy Laboratory.
"This requires the students to carry out quite difficult characterization analysis using diffraction contrast, which complements the TEM theory course also given in MSE," Sinclair said.
"Not only do the students receive a first-rate educational training, but their appreciation of Ann's efforts are consistently expressed by one of the top teaching scores in the department – typically being at the 4.8-4.9 level on the current 1.0-5.0 scale. This far surpasses that of most regular MSE faculty for whom teaching is their primary profession."
Sinclair also praised Marshall for her publication record, which he described as "extensive," often involving co-authorship with students.
"On many occasions, she has been the intellectual leader, in others she has guided the students to obtain meaningful data," he said, noting that "her work has had significant impact with close to 4,000 total citations and an h-index of 28. This level is expected of a full professor at a major research university like Stanford, but not for someone for whom research and publication is only a small fraction of her job description."
Marshall's teaching talents also won praise from Paul McIntyre, professor of materials science and engineering, and director of the Geballe Laboratory for Advanced Materials at Stanford.
"Ann has taught several generations of graduate students across Stanford the practical aspects of electron microscopy, and she has provided many of them with deeper insights into image interpretation, best practices in specimen-making, and the advanced imaging and diffraction methods needed to solve critical research problems," McIntyre wrote in a letter nominating Marshall for the award.
"Ann's work has had a tremendous impact both in terms of the important research discoveries that it has enabled and the high quality of electron microscopy for which Stanford is known."
McIntyre said Marshall had trained his students and collaborated with his group for the better part of a decade.
"In this time, we've written many papers on which Ann has been a co-author," McIntyre said. "Her intellectual contributions to the work we have done in understanding the growth of semiconductor nanowires have been essential.
"Working closely with my students, she has also pulled up the level of their materials characterization research, which has helped them perform analysis worthy of publication in the leading journals of our field."
McIntyre called special attention to Marshall's discovery of "gold nanoparticles with hexagonal close packed crystal structure, solidified at the tips of our germanium nanowires at the end of their growth by the vapor-liquid-solid process."
"This is the first-ever observation of the synthesis of gold in the hexagonal crystal structure at ambient pressures, and suggests the possibility of solidifying other metals in unusual structures on these nanoscale pedestals," he said. "Ann's discovery was published in 2010 in Nano Letters, a highly selective scientific journal."
Ai Leen Koh, whose research as a doctoral candidate at Stanford involved extensive use of the TEM, said that one of the most challenging aspects of that work is specimen preparation. She said a bulk material needs to be thinned down to electron transparency – with thicknesses less than 100 nanometers – in order to obtain useful information about the material structure with TEM.
"To make such thin samples involves a series of mechanical grinding, polishing and ion milling steps, each of which is not trivial, and it is easy to lose one's sample during every step of the process," Koh wrote in a letter nominating Marshall for the award.
"One of my projects involved studying multilayer-structured magnetic nanoparticles and viewing the individual layers in TEM, and my first couple of attempts at making these cross-section samples turned out to be a complete disaster," said Koh, an alumna who earned master's and doctoral degrees in mechanical engineering, in 2005 and 2009, respectively.
"After spending 50 hours in the lab and coming out with no sample, I went to Ann to discuss what could have gone wrong," she said. "During my next attempt at sample preparation, Ann would come down to the lab at the end of every intermediate step to check that the sample was OK; [she] worked with me to start the next process and gave me pointers that are crucial in terms of making a good sample. I successfully made my first TEM cross-section sample with Ann's help."
Koh, who returned to Stanford in 2010 and now helps manage the TEM Lab, said Marshall continues to inspire her with "her dedication in training new users, managing the specimen preparation laboratory and making sure that all the equipment is working properly so that things can get done."
James Wittig, associate professor of materials science and engineering at Vanderbilt University, said Marshall's course on using transmission electron microscopy for materials characterization helped shape his career as an electron microscopist.
"In the last 33 years, Ann has trained many hundreds of Stanford graduate students in the use of TEM, both with her laboratory course as well as hands-on collaborative research assistance," Wittig wrote in a letter nominating Marshall for the award.
"The philosophy at Stanford, which requires graduate students to become independent trained users of the electron microscopy facilities, differs from many universities where only technicians are allowed to run the instrumentation. Only with Ann Marshall's contributions has this system been successful."
"Ann has been extremely successful in setting an example and being a mentor to all the students involved in materials research even after they have graduated and are carrying out their own investigations," Subhash L. Shinde, manager of the Concentrating Solar Technologies Department at Sandia National Laboratories in New Mexico, wrote in a letter nominating Marshall.
"This is evident from the cluster of old colleagues that gathers around her in the conferences that she attends. The discussions are filled with laughter in addition to exchange of the latest scientific information – this is Ann's specialty, being informal as well as highly scientific."
"Very simply put, Ann Marshall is a 'treasure' at Stanford," Reinhold H. Dauskardt, professor and associate chair of the Department of Materials Science and Engineering, wrote in a nominating letter.
"In her own right, she is a talented and dedicated scientist – however, what really sets her apart is that she has worked selflessly and with dedication to support a generation of graduate and undergraduate students at Stanford.
"With little recognition and with selfless modesty, she has helped, mentored, nurtured and trained more graduate students than I can count. She has been a core member of the technical staff of the broadly used materials characterization facility at Stanford, and has been instrumental in helping the facility evolve the world-class capabilities it has now."
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