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Laser on nanotubes

A professor from UFMG receives an international prize for his contribution to nanoscience

Léo RamosAdo Jório in his laboratory: cutting-edge research in a subject that is of interest to several disciplinesLéo Ramos

Physicist Ado Jório de Vasconcelos, 39, a full professor at the Federal University of Minas Gerais (UFMG), was honored in April with the ICTP 2011 Prize, which distinguishes original contributions in physics and mathematics by scientists from developing countries under 40 years of age. The prize, awarded since 1982 by The Abdus Salam International Centre for Theoretical Physics (ICPT), a traditional theoretical physics and mathematics research institution, whose headquarters are in Trieste, Italy and supported by the Italian government, the International Atomic Energy Agency (IAEA) and UNESCO. The ICTP recognized the work of the researcher from Minas Gerais, with the application of a technique known as Raman spectroscopy for identifying the properties of carbon nanotubes.

Carbon nanotubes are extremely strong, fine cylinders (their diameter is 100,000 times smaller than a hair). Good thermal conductors, they can behave like metals or semiconductors, properties that make them important ingredients in the production of electronic devices and light materials. Jório helped to identify new applications for carbon nanotubes by using Raman spectroscopy to characterize them. “Nanotubes are produced in their billions and their properties are variable. They vary in diameter and in the helicity of their bonds. My work had an impact because we were able to isolate them one by one and discover a world of properties,” explains the researcher from Minas Gerais.

“Jório’s work is an example for many on his continent and beyond it,” said Erio Tosatti, a scientist from the ICTP, when justifying the award. “It’s not very common to find high level experimental work in developing countries, because of the difficulties of working in an environment where there are few resources.” The winner will be given € 3000, a sculpture and a certificate. This is the fourth time that a Brazilian has won the ICTP Prize. In 1992 it was awarded to Elcio Abdalla; in 1984, to Ricardo Osório Galvão, both from the Physics Institute of the University of São Paulo; and in 1988, to José Nelson Onuchic, a former professor from USP’s Physics Institute in São Carlos, who is currently a researcher at the University of California at San Diego.

Ado Jório has been working with carbon nanotubes since he did a post-doctoral course at the Massachusetts Institute of Technology (MIT) in 2000, and since then he has become an international benchmark in the subject. “As the applications for nanotubes are of interest to various fields of knowledge, such as chemistry, physics, biology, materials science, medicine and engineering, the 152 articles I’ve written have already been cited more than 10,000 times, which is a very substantial figure,” he says. On the list of the 26 Brazilian scientific articles published between 2001 and 2005 that received more than 200 citations, compiled by the USP dean of research, Marco Antonio Zago, for the Web of Science database, Jório is one of the authors of two works – both deal with the characterization of carbon nanotubes using Raman spectroscopy. In one of them, published in New Journal of Physics, the researcher is the main author. In the other, published in Physical Review Letters, he is the co-author along with Marcos Assunção Pimenta, his PhD supervisor, also a professor at UFMG and a pioneer in the study of carbon nanotubes in Brazil (see Pesquisa FAPESP issue 187).

Ado Jório has an H 52 index – the H index is a measure that relates the quantity and impact of the production of a researcher. An H 52 index means that at least 52 of his/her articles have had  repercussion to the point of being cited in 52 other works. The H index varies a lot between fields of knowledge, because the impact of an article depends on the size of the community of researchers. Its creator, physicist J. E. Hirsch, from the University of California at San Diego, calculated that, on average, Nobel laureates have an H 30 index. The repercussion of his articles, observes Jório, was the catalyst for hundreds of international collaborations and has already resulted in his delivering some 50 talks at international congresses.

Vibration frequency
Raman spectroscopy is a technique discovered 90 years ago that analyses the light frequencies that fall on a substance and the light that is reflected back off it. The energy difference between the incidental radiation and the scattered radiation corresponds to the energy with which the atoms in the area studied are vibrating. This vibration frequency enables the discovery of how atoms are linked, provides information about molecular geometry and about how the chemical species present interact between each other and with the environment, which helps measuring their mechanical, elastic, thermal and electronic properties. The phenomenon was identified in 1928 by the Indian physicist Chandrasekhara Venkata Raman, who won the Nobel Prize for Physics two years later. The technique has been useful, for example, in identifying the materials used in works of art. It gained in importance in the 1960s after the arrival of laser rays and is widely used to characterize carbon materials. Use of the technique on a microscopic scale enables the study of areas as small as 1 µm (10-6 m) in diameter, which is why it is useful in the study of nanotubes, which boomed as from the 1990s.

Between 2007 and 2009, Ado Jório worked at the National Institute of Metrology, Quality and Technology (Inmetro), helping develop methodologies for measuring and analyzing the properties of carbon nanostructures. “In addition to the progress of knowledge, I was always concerned about developing effective uses for the research. I focused on the issue of the metrology of this technique with Inmetro,” says the researcher, who is also interested in the management of innovations at universities. Since 2009, he has been directing the Transfer and Technological Innovation Coordination Department at UFMG, a center for technological innovation that is responsible for managing intellectual property, the transfer of technology and the formation of companies within the institution. Born in Belo Horizonte, Jório graduated from UFMG, where he also did his PhD, took a specialization course at the Centre National de la Recherche Scientifique (CNRS) in France, and got his post-doctoral qualification at MIT. He is married and has two daughters.