J. Phys. Chem. C 2010, 114, 7213–7216
7213
Biography of Martin Moskovits Martin Moskovits was born in Braila, a small but bustling port city in eastern Romania, on April 13, 1943, the older child of Emanuel, a jeweler, and his wife Ana. He has a younger sister, Leny. In 1953, Martin emigrated to Canada with his family after spending a year in Israel and several months traveling through Europe. The family settled in Toronto where Martin completed his secondary school education at the Harbord Collegiate Institute and enrolled in the Mathematics, Physics and Chemistry Program at the University of Toronto. Although his love was primarily mathematics and physics, he was encouraged by Professor Frank Wetmore, a charismatic physical chemist to veer toward chemical physics. “All of the great future developments in physics will occur at the interface with chemistry,” Professor Wetmore predicted. Martin completed the challenging undergraduate curriculum and decided to focus his study on the interdisciplinary field of physics and chemistry in his upper years, completing his bachelor’s degree in 1965. (His friends described him as “brilliant and generously helpful” as they struggled through a tough curriculum.) During his undergraduate years, Martin cofounded an electronics company, OHM Distributors and Manufacturers Ltd., with two of his classmates: Paul Hoffert (currently a successful professional musician) and Roelof Oostwoud (a renowned operatic tenor). The company successfully manufactured and sold high quality microphones and electronics for music reproduction in Canada. At the same time, Martin began his graduate studies in chemical physics under Professor Michael Dignam in the department of chemistry at University of Toronto. Professor Dignam’s love of mathematics 10.1021/jp908943p
and theory greatly influenced Martin’s approach to research. Martin’s thesis dealt with the changes in the optical properties of thin metal films that result from the adsorption of gases. It was during his Ph.D. work that he came across the optical anomalies produced by surface plasmons excited in submicroscopic metal surface roughness. Upon completion of his Ph.D. in 1971 Martin joined Alcan Research and Development in Kingston, Ontario as a research scientist. Here he investigated oxidation of aluminum while attending to other more practical duties. The work focused on the use of alloying additives such as strontium, to reduce the formation of aluminum-magnesium oxides during remelting of scrap aluminum, and generally to understand the nature of aluminum interfaces at a time when aluminum companies were looking for surfaces that bonded well to materials such as Teflon. That work resulted in a patent and two publications. It was also at Alcan the he learned of the intriguing properties of anodic aluminum oxide that nourished a research interest that spanned the next 25 years of his career. After two successful years at Alcan, Martin decided to return to Toronto to be closer to his family. In 1973 he returned to his alma mater as a visiting assistant professor which soon was elevated to a tenure track position. Martin advanced quickly, attaining the rank of full professor in 1982, and serving as departmental chair from 1993 to 1999. While at the University of Toronto, he assembled a colorful palette of research activities that included matrix isolation spectroscopy, Raman optical activity, metal clusters, catalysis, thin film science, colloid chemistry, optical properties of materials, scanning probe
Published 2010 by the American Chemical Society Published on Web 04/22/2010
7214
J. Phys. Chem. C, Vol. 114, No. 16, 2010
microscopy, nanotechnology, and, of course, surface enhanced Raman spectroscopy (SERS). In his early training, Martin developed a keen interest in the small metal clusters, small atomic assemblies bridging the discontinuous territory between metal atoms and bulk metals, that possess properties that varied, sometimes dramatically, as their dimensions spanned those two solitudes. Upon his return to U of T, Martin began a fruitful collaboration with his colleague Geoffrey Ozin and together established a program to record the spectra of small metal clusters isolated in frozen rare gas matrices. Ozin, Moskovits, and their students and postdocs published an impressive body of work on matrix isolated metal clusters and their binary compounds with various small molecular ligands using infrared, Raman, and UV visible spectroscopies to probe the vibrational and electronic states of metal clusters. This work was some of the earliest in the field of “cluster science” that flourished in the 1980s and was taken so successfully into the gas phase by the late Richard Smalley and other eminent scientists. Many of the questions posed in the work on metal clusters were antecedent to the size-dependent properties of materials that underlie present-day nanoscience and nanotechnology. One of the major accomplishments of the Moskovits’ group during the latter days of cluster science was to construct a massselected cluster beam apparatus (one of only three working systems worldwide) to examine small Au, Ag, and Fe clusters in an inert gas matrix using resonance Raman spectroscopy. That feat was led by Tom Haslett. As work progressed toward producing ever-larger clusters of Ag and Au, one eventually had to confront the question of the development of the localized surface plasmon as a contributor to the optical properties of the clusters. It all seemed to come full circle and embrace another phenomenon in which Martin became interested: SERS. Professor Richard Van Duyne (Northwestern University) had reported observing inordinately intense Raman scattering from pyridine adsorbed on silver electrode in his landmark paper of 1977. Martin made his first seminal contribution to this field in 1978 with a paper in which he proposed that it is surface plasmons that are largely responsible for the extraordinary enhancement of the Raman scattering signal observed by Professor Van Duyne. In that first SERS paper Martin predicted that the effect, which up to that point had only been observed on silver electrodes subjected to oxidation-reduction cycles, would also be observed in cold-deposited films and in colloidal metal systems and that metals which exhibit surface plasmons with high quality factors such as the coinage metals and the alkalis would be the ripest candidates as SERS-active systems. All of these predictions were realized within a year of the publication of this paper. His work also emphasized the preeminent role of coupling among nanoparticles or other nanostructures in creating the superstrong optical fields that are responsible for the most intense SERS signals including, under favorable circumstances, optical fields strong enough to allow SERS of single molecules to be detected. Martin also showed that in SERS one often observes very intense Raman-forbidden bands and explained this in terms of the unusually sharp gradients in the optical electric field near metal surfaces that permit dipole selection rules to arise through multipolar tensor elements of the system. These ideas were expanded to other spectrocopies at surfaces. His fundamental contributions to the understanding of SERS were acknowledged very early on by several authors. As an example out of many, Professor Kerker (Clarkson University) reported that his group undertook their study of fields around
Tay isolated colloidal particles as a result of the prediction that Moskovits made that SERS would be observed for true colloids. Professor Metiu (University of California) and his colleagues who carried out pioneering calculations on SERS and especially SERS of coupled particles stated in their 1980 report that “The first attempt to explain the role of roughness in SERS has been made in a pioneering study by Moskovits. He models the rough surface by assuming that it consists of silver islands seated on the top of the flat silver surface...the island provides the resonating electronic states, which are the islands electromagnetic modes, while the molecules participate by providing vibrational nuclear motion.” Although colloids produced the simplest SERS-active systems, Martin’s experience with ultrahigh vacuum systems prompted him to carry out his group’s early experiments in SERS on cold-deposited films. Those studies were carried out by a number of (now) eminent surface scientists including Professors Robert Wolkow and Peter McBreen, while much of the fundamental SERS work with colloidal systems was carried out by Jung Sang Suh, now professor at Seoul National University. During the 1990s the Moskovits group also carried out a series of ground-breaking studies on the optical properties of disordered metal films confirming the prediction by Stockman and Shalaev that self-affine and self-similar fractal colloidal aggregates would in general possess localized surface plasmon normal modes in the scaling region. To prove this prediction experimentally the group built one of the first low-temperature UHV scanning tunneling microscopes and developed scanning near-field optical microscopy expressly to demonstrate the localization of optical fields in fractal plasmonic aggregates. That work was led by Vladimir Shalaev, Din Ping Tsai, and Peng Zhang, who are all now successful professors. In 1985 Martin wrote a review paper on SERS in which he enunciated some of the challenges that even now remain current in the field and stated his position on the interplay between the plasmonic and the so-called chemical origins of SERS that has only recently been vindicated. That paper continues to be the most-cited reference work on SERS both in terms of total citations (>2100) and new citations per year (>200 in 2008). Martin’s work stands at the forefront of the SERS research in which he had made many seminal predictions that had withstood the test of time. The only prediction about SERS that he seems to have got wrong is this statement which appeared in this 1985 review. “...SERS has reached its zenith and has begun its Spenglerian decline, it is equally clear that it will live on a while through its various progeny, having served as a wonderful impulse that has changed somewhat the momentum of surface science.” The field of SERS has in fact flourished and been rejuvenated by many exciting new studies over the last two decades, including those from Martin’s own work. Martin continues to contribute to the field of SERS through the development of engineered plasmonic nanostructures which produce intense, stable, and reproducible SERS signals and through the application of SERS to chemical and biological sensors. Martin is probably the earliest implementer of porous anodic alumina (PAA), or, synonymously, anodic aluminum oxide (AAO) as a template for the synthesis of nanowires and nanotubes. While working as a research scientist at Alcan, Martin and his colleague David Goad first reported the observation that AC electrolysis deposits metal in the nanopores of PAA, an oxide that is formed when aluminum is preanodized in an acidic electrolyte. This work was reported to the company
J. Phys. Chem. C, Vol. 114, No. 16, 2010 7215 in 1971, and appeared in print in 1978 in a paper coauthored with David Goad. In the 1980s, access to e-beam lithography and nanofabrication facilities was very limited, Martin’s group exploited PAA innovatively to fabricate a variety of nanostructures for applications such as catalysis and nanowire-based magnetic recording media. In the 1990s, the group published a large number of original papers illustrating (i) the synthesis of nanowires and nanostructures using PAA templating, (ii) the fabrication of aligned and highly ordered carbon nanotubes, (iii) the direct synthesis of compound semiconductors in PAA, (iv) the use of Ni nanowires fabricated in PAA as efficient targets for X-ray laser applications, (v) the use of nanowires and nanotubes synthesized in PAA as elements in single-electron-tunneling devices, (vi) the use of PAA as a contact mask in reactive ion etching nanosized holes, (vii) the use of nanowire and carbon nanotube arrays in field-emission display applications, and (viii) the fabrication of sensors with the nanowires functioning as the active channel medium in a field-effect transistor. It is interesting that prior to about 1990, the prefix “nano” was not in common use in the materials science community. Nanomaterials were referred to as “submicroscopic particles”, “colloidal particles”, and “high-aspect-ratio micro- and mesostructures”. One of the earliest uses of the term “nanoparticle” was by Martin in an invited talk at the 1991 American Chemical Society Meeting in Atlanta titled Nanoparticles Fabricated in Nanotemplates (ACS Meeting, Atlanta GA, Apr. 17, 1991), about which he tells me he submitted at the time as a bit of tongue-in-cheek. Martin was also known as a charismatic academic administrator. In 1993, he succeeded his mentor, Professor Michael Dignam, as Chair of the chemistry department. The most notable achievements of his time as Chair were the recruitment of about a dozen new faculty members, an expansion of the graduate program, and the establishment of the popular J. C. Polanyi Nobel Laureate Lecture Series. Among the many highlights of his chairmanship, Martin is best known for transforming the department through the construction of the Davenport Building and the renovation of the aging Lash Miller Chemical Laboratory into a state of the art teaching and research facility (a task completed by his successors Professors David Farrar and Scott Mabury). The Davenport building has been vital to the recruitment of graduate students and new faculty members over the past decade. During this eventful transformation period, Martin also served as mentor to many junior faculty, colleagues, and scientists both in the department and in the university community at large. In 2000, shortly after stepping down as the Chair of the chemistry department, Martin was recruited as Dean of Science and Professor of chemistry and biochemistry at University of California in Santa Barbara. While serving as Dean, Martin nevertheless maintained a productive research program which built on his successful materials research program and broadened into many device applications. During his deanship, Martin actively promoted interdisciplinary synergy, worked to boost graduate enrollment, and saw some 70 new science faculty recruited at UCSB. He also established an impressive development program to help secure funding for new programs in the Science Division. In 2007, after approximately 7 years of service as dean, Martin took unpaid leave from UCSB to take on the position of Chief Technology Officer at API Nanotronics Corporation, a publicly traded company specializing in the manufacture of electronic and magnetic products, for which he founded a subsidiary (API Nanofabrication and Research Corp.),
which manufactured optical components and sensors fabricated using a suite of nanofabrication technologies. Professor Moskovits is the recipient of several prestigious awards. He is a Fellow of the American Association for the Advancement of Science, the Optical Society of America, and the Royal Society of Canada. He was awarded the Gerhard Herzberg Award of the Spectroscopy Society of Canada (1993), The Unilever Award of the Royal Society of Chemistry (London) in Surface and Colloid Science (1993), a Killam Fellowship (1989-91), a Guggenheim Fellowship (1986-87), the 400th Anniversary Johannes Marcus Marci Medal of the Czech Spectroscopy Society (1999), the Canadian Society for Chemistry EWR Steacie Award (2000), and a NanoTech Briefs Nano 50 Innovator Award (2008). He also served as a member of the Advisory Board of Steacie Institute for Molecular Sciences, and the National Institute for Nanotechnology of National Research Council Canada. He has been a member of the Research Corporation’s Award Program Advisory Committee, a member of the Board of Sansum Medical Research Institute, and a member of the U.S. Department of Energy’s Basic Energy Sciences Advisory Committee. He was the founding director of the Nanoelectronics Program of the Canadian Institute for Advanced Research (2000-2004). Among all of the academic and administrative achievements, Martin’s greatest pride lies in the 80 students and postdocs who collaborated with him. Martin has always given his students and postdocs his unconditional support throughout their academic years and beyond their residency in his group. For many of us, Martin continues to provide encouragement and guidance even years after our departure from his group. Martin inspired his students toward pursuing innovative and fundamental questions and encouraged us to acquire a broad understanding of the theoretical underpinning of our experimental observations. Many of his graduate students and postdocs went on to occupy key positions in academia, industry, and government research laboratories worldwide. Quoting from his former students, “Martin’s affection towards his students is very much like that of a protective parent. He gave us the freedom to explore our own experimental path and was always there to guide us through the forest when we got lost.” He always defended and supported his group members and provided them with what they needed to excel in the challenges of graduate studies or postdoc experiences and guided them in their selection of future professions. He acknowledged his pride in those who studied with him at a farewell party on the eve of his departure from the University of Toronto, in front of a room packed with colleagues, staff and honorary guests, generously crediting his graduate students and postdocs (past and present) for the achievements and successes he’d had at the University of Toronto. Another former student recalled that Martin was often ahead of his time. “Students working with Martin in the 70s were exposed to concepts, subjects, challenges, interdisciplinary blends and experimental techniques that continue to gain in currency three decades later. These include plasmonics, surface selection rules, polarization modulation spectroscopies, control of properties at the nanoscale, targeted synthesis of functional nanostructures, and surface studies of complex systems. The boundless enthusiasms and curiosity that he communicated for his research and, for the work of others in a variety of different fields of sciences, made him an inspiring mentor. His mentorship came with great kindness, great humor, wonderful dim sum lunches, and the individual sustained attention was more than an extra bonus.”
7216
J. Phys. Chem. C, Vol. 114, No. 16, 2010
Those who know Martin also recognize that his talents span many domains outside of science. His quick wit and exceptional sense of humor were always the highlight of any social occasion. He is an accomplished amateur vocalist (he was a member of several Toronto Choirs), a talented pianist, a master cook and able to identify many edible (at least so far) species of wild mushrooms. He is fluent in several languages. He is married to his longtime companion, friend, and life guide Linda and has four children Allyson, Steven, Joshua, and Leslie.
Tay As a graduate from Professor Moskovits’ group in the later part of his time at University of Toronto, I want to extend my profound thanks to the many former group members, colleagues, and classmates of Martin’s for sharing their reminiscences on his long career in industry and academia.
Li-Lin Tay National Research Council Canada JP908943P
