5th Brazilian Materials Research Society Meeting (SBPMat)
October 8 - 12, 2006 | Florianópolis, Brazil
In co-operation with the Brazilian MRS
(Sociedade Brasileira de Pesquisas em Materiais)
Day 4 - Wednesday
The 5th Brazilian Materials Research Society Meeting (SBPMat) completed its pernultiminate day in Florianópolis, Brazil, as it headed towards its natural and very successful conclusion on Thursday. Day 4 included the conference dinner and a rock band at the end of the day in addition to the regular slate of events.
“Global collaboration – among scientists, engineers, educators, industry and governments – can speed the transformation of new knowledge into new products, processes and services, and in their wake produce new jobs, create wealth, and improve the standard of living and quality of life worldwide.”
U.S. National Science Foundation Director Arden L. Bement, Jr.
TEM-based EELS Analysis in Materials Science
The first plenary talk of the day was given by Prof. Christian Colliex (Univ. Paris-Sud, Orsay, France) on TEM-based (Electron Energy Loss Spectroscopy) EELS analysis. Colliex gave a broad overview of EELS local analysis and its applications in materials science. EELS measures the energy loss suffered by elastically scattered primary electrons and Colliex explained the fundamental principle of an EELS measurement, as well as associated spectral domains of interest. EELS can be used to map different physical parameters including electronic, magnetic and optical characteristics. It can be used to map the nature, position and bonding of atoms responsible for structural properties of materials with high accuracy, including defects, interfaces and nanomaterials.
Colliex then explained the details of EELS measurements in a TEM using the STEM mode. He discussed differences between the two techniques used - parallel fixed illumination (energy filtered TEM) and covergent scanned illumination (STEM/PEELS). He focused on nano-scale materials and described how the EELS technique is very useful and ideal for obtaining topographic, atomic structural and chemical information. He described the use of core-loss EELS spectroscopy for elemental mapping, bond mapping and valence state determination, and showed various results, for example for BN nanotubes and nanoparticles. He described how EELS can be used to determine interface states using the Energy Loss Near-Edge Structure (ELNES) fine structure. EELS is clearly a very powerful technique in materials science. Colliex concluded by mentioning that future work in the field involved improving the spatial resolution and improving the energy resolution at very low energy losses.
Funding Opportunities in Materials Research with NSF
The final plenary presentation of the conference was given by Dr. Thomas Weber, Director, Office of International Science and Engineering, National Science Foundation (NSF), USA, focusing on international materials research collaborations and funding. He first gave an overview of NSF support for materials research, specifically through the Division of Materials Research (DMR). In addition to a total of 832 grants in 2006, more than 5,000 reseachers used DMR supported facilities in 2005. Weber then described the international activities of NSF. He stressed that science and engineering research is a global activity, and international collaborations for research and education are essential for the advancement of knowledge. He discussed programmatic support for international materials collaborations, including the international materials institutes and coordinating with other agencies. He detailed the workings of collaborations that involve NSF funding.
Weber then focused on the Materials World Network (MWN) program of the Division of Materials Research of the NSF. The MWN program supports the US side of collaborative research partnerships. Over 50 countries, in addition to the European Commission and the European Science Foundation, are partners with the NSF. Of particular interest for Brazilian scientists is the Inter-American Materials Collaboration (CIAM) partnership started in 2003 which involves 9 countries in the Americas. Weber presented specific examples of international collaborative projects that were successfully funded. He stressed the educational aspects of the projects including exchanges of graduate students and young scientists. He also described the International Research Fellowship Program for US citizens and residents for post-doctoral work outside the US. He detailed the Pan-American advanced studies institutes (PASI) in collaboration with Latin American countries for short courses for young scientists. More information is available at the NSF website (http://www.nsf.gov/) or by contacting Dr. Weber at email@example.com.
We just love this meeting!
Symposium A: Tribology and Surface Engineering
Room Temperature Mechanical Properties and Tribology of NICRALC and Stellite as Cast Alloys
W. S. Silva (Universidade de São Paulo), in his presentation on Tuesday, talked about NICRALC which is a family of casting alloys proposed as a substitute for abrasion and erosion resistant cobalt alloys. NICRALC microstructures contain hard chromium carbides dispersed in a continuous Ni-Al-Cr ordered intermetallic matrix. The motivation for the work was to determine whether NICRALC could substitute for STELLITE 6, a more expensive cobalt based alloy traditionally used for the same purpose. Mechanical properties of the investment cast alloys were evaluated by compression, hardness and fracture toughness measurements, all at room temperature. Tribological properties were evaluated by cavitation, rubber-wheel wear, reciprocating wear and block-on-ring lubricated wear (FALEX) tests. The wear and fracture mechanisms were studied using SEM imaging of the worn or cracked surfaces. Results show that NICRALC is softer than STELLITE and therefore is not as good with regard to tribological behaviour. The work is continuing using SEM and XRD of the collected debris.
[View extended abstract]
"I think we can skip this and
Symposium F: Nanostructures and Defect Analysis by Electron Microscopy
Elemental Mapping of Nano-Materials Using TEM and STEM
With the current burgeoning interest in nanomaterials and the associated development of a wide range of nanomaterials, it is becoming crucial to be able to determine compositions at the nano-scale, at ~1 nm. In his presentation, Dr. Jim Bentley (Oak Ridge National Laboratory (ORNL)) described the use of analytical electron miscroscopy techniques to determine nanoscale compositions. In particular he focused on two techniques, energy filtered TEM and spectrum imaging in STEM mode using energy dispersive X-ray spectroscopy (EDS) and EELS. The measurements were performed at the ORNL SHaRE user facility.
Bentley then gave specific examples of experiments performed. These included a systematic study of CoCr(TaPt) magnetic recording media, as well as CoCrPtB alloys and CoCrPt perpendicular media. He described the extraction of elemental maps for CoPtTiO2 perpendicular recording media from the EDS/EELS spectrum image. Significant Co, but no Pt was observed at the grain boundaries. The TiO2 stoichiometry could also be determined using quantitative EELS. Bentley also discussed work on reaction ball-milled Y-Ni-O nanostructures for the development of oxide-dispersion strengthened (ODS) steels. He described the composition mapping of nanoscale MgAl2O4 spinel. Bentley ended by stating that the techniques described here can be used to study real materials with technological importance. The future direction is towards deep sub-0.1 nm imaging and EELS with single-atom sensitivity. He concluded by mentioning the new Advanced Microscopy Lab (AML) at ORNL housing four probe-corrected TEMs.
[View extended abstract]
Courtesy: J. Bentley, ORNL
EFTEM elemental mapping of Y-Ni-O nanostructures
in material ball milled at 100°C. Ni, Y and O maps
were combined to produce the RGB image.
Symposium I: Nanostructured Biological Materials
A Summary – by Prof. Osvaldo N. Oliveira Jr.
The variety of topics included in the symposium illustrated the interdisciplinary nature inherent in the use of materials science in connection with biological materials. The main topics covered included:
1) Novel materials for tissue engineering, not only for hard structures such as bones, but also for cardiac and skin tissues. Functionalized coatings and edible films were also important.
2) Immobilization of biomolecules for several uses, e.g. biosensors, cell growth and biochips, in addition to serving for mimicking cell membranes in the study of fundamental biological processes.
3) Novel systems for drug delivery.
4) Applications in biosensors of various types, including possible use in diagnosis that may be tried in prototypes in the near future. One should highlight, for instance, the possibility of diagnosing tropical diseases, which is particularly important for Brazil.
Also presented in the symposium were a few papers containing quantum chemical calculations and molecular dynamics and Monte Carlo simulations, thus pointing to an increasing – and badly needed – collaboration between theoreticians and experimentalists.
Impedance Based Bio-Chip to Monitor Interactions between Cells
H.L. Gomes, of the University of the Algarve, Portugal, described the development of a technique that uses changes in capacitance to monitor the interaction between immune system cells (hemocytes) with intruder cells (parasites). The work was started and is funded because oysters on the Atlantic coast (Ruditapes Decussatus) were being killed by a parasite, the Perkinsus atlanticus. It was found that some of the oysters were immune, suggesting differences in their immune system. The parasites show a peculiar behavior; they aggregate in clusters when they feel threatened by the hemocytes. The level of this aggregation may provide a measure of the immune system efficiencies. The cell aggregation causes impedance (capacitance) between a microelectrode and a large reference electrode, which can be monitored.
[View extended abstract]
Symposium J: 2nd Brazilian Symposium on Microscopy Applied to Forensic Science
Firearms Comparisons in a Forensic Ballistic Laboratory
In forensics, the analysis of firearms and bullets is a critical part of investigations. Dra. Andrea P. C. Campos (Departamento de Polícia Técnico-Científica (DPTC), Rio de Janeiro), in her talk in symposium J, outlined the techniques involved in comparing firearms and determing whether bullets and cartridge cases can be linked to a specific firearm. The reproductibility and uniqueness of machining marks on bullets and cartridge cases, also called ballistic fingerprints, allow a firearm examiner to identify a specific weapon used in a crime. The primary instrument used is a comparison microscope, which allows for side-by-side observations and comparison of microscopic characteristics. For inconclusive cases, electron miscroscopy is also used. In recent years, automated comparison systems have become a critical tool in forensic labs. Several countries have built databases of ballistic images of bullets and cartridge cases. These systems significantly speed up the comparison process, however, the final decision is still the examiner's. Finally, Campos gave specific examples of crimes solved using firearms comparisons.
[View extended abstract]
Serial Number Restoration in Metals and Polymers
H. Katterwe, of the Forensic Science Institute, Wiesbaden, Germany, gave a fascinating look into the criminal world when he talked about the science of restoring serial numbers to metal weapons and to plastic stolen goods. Automatic hardness measurement machines made it possible to cover the surface of a gun, for example, and detect the regions of increased hardness that are present after the serial number has been stamped on the weapon even if the number has been filed off.
Courtesy: H. Katterwe, Forensic Science Institute, Wiesbaden
In this example the number “1” shows up where
the material is harder and the indentation is shallower.
Plastics can be examined by exposing the object to solvents that make the polymer chains swell and the compressed regions under the number expand more than the surrounding regions. It is a form of shape memory. An interesting story occurred when a forensic scientist in Germany was making “lebkuchen” and found that the cloves used during the cookie recipe exposed makings on plastic containers. Clove powder has now become an important tool in the fight against crime.
[View extended abstract]
Symposium M: Advanced techniques of Microscopy for Characterization and Modification of Materials - MICROMAT
3D Orientation Microscopy in a FIB-SEM
Alice Bastos da Silva, from the Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany, gave an interesting talk on Tuesday on a new SEM-EBSD (scanning electron microscope – secondary electron backscatter) set up with a Focused-ion-beam (FIB) system in a dual beam microscope. Samples can be investigated by removing a successive set of thin slices of material (minimum thickness ~ 50 nm) from the sample surface by sputtering with a high-energy ion beam (Ga+ source) and then measuring the surface using electron backscatter diffraction (EBSD) patterns. After the milling process, the sample is tilted to the EBSD position, which means a tilting angle of 70° in order to observe the diffraction pattern. The microstructure of the surface can also be analyzed by conventional 2D EBSD-based orientation microscopy. By successive sputtering and EBSD measurements the 3-dimensional microstructure can be built up. The machine can be made to function automatically.
Electro-deposited cobalt nickel was investigated to understand the growth of columnar grains. The results that were shown in the presentation took about a week to obtain and Alice spent 20 hours a day in the laboratory during that week. Some of the difficulties with the technique are that the etch rate depends on the grain orientation so that it is difficult to maintain a smooth surface, the ion beam tends to make the surface amorphous, and the gallium tends to interact with some samples.
[View extended abstract]
ROUNDTABLE: INDUSTRIAL DEVELOPMENT VS ACADEMIC RESEARCH IN BRAZIL
A special roundtable session in Portuguese was held in the evening to discuss how academic materials research in Brazil relates to industry and the development of products. The panel included Prof. Angelo Fernando Padilha (Escola Politecnica da USP) and Prof. Calos Alberto Schneider (UFSC) from the academic side, and Mr. Antonio Claudio C.M. Sant'Anna (PETROBRAS) and Mr. Roberto Binder (EMBRACO) from the industrial side. After each of the panelists gave a presentation, the session was opened for discussion. The major issue of concern in Brazil is that while scientific research is very strong, indications are that not much of it gets into real industrial applications. For example roughly 1.8% of peer-reviewed scientific publications in the World are by Brazilian researchers. However, only 0.02% of patents world-wide are from Brazil. This indicates a large gap in the transfer of technology, from academia to industry and a large disconnect between the two. The discussions centered on what could be done to bridge this gap and to have academia and industry work together. In addition, 80% of research in Brazil is conducted in Universities. It is apparent that the two groups do not speak the same language. The two companies represented in the panel, PETROBRAS AND EMBRACO, do indeed conduct research within and they also fund research in Universities.
While there were no clear solutions to the problem, there was a consensus that academic researchers and industry in Brazil should work more closely for furthering and developing practical technologies. The roundtable session was very well attended, with about 400 attendees at the start of the session, and with vigorous discussions. The hope was expressed that co-operation between academic researchers and industry would grow, and this will benefit the materials research community in Brazil as well as technological developments as a whole in the country.
The conference dinner was held in the evening. The entertainment included a wonderful band from South Brazil. All the attendees had a good time celebrating a successful conference.
© Materials Research Society, 2006