B-MRS (SBPMat) newsletter. English edition. Year 3, issue 8.


 

Brazilian Materials Research Society (SBPMat) newsletter

News update from Brazil for the Materials community

English edition. Year 3, issue 8. 
XV Brazil-MRS (SBPMat) Meeting - Campinas (SP), Sept 25-29, 2016 

1,909 abstracts have been accepted to be presented at the XV SBPMat/ Brazil-MRS Meeting. 

Registration: Registration for the event is open. Here.

Awards. In addition to the Bernhard Gross Award, this year there will also be an ACS award (American Chemical Society). The winners have to be present at the closing ceremony in order to receive the prizes (Sept 29, from 11h45 to 14h00).

Program. The short and full (symposium by symposium) versions are available on the website. Here.

Special Sessions – Science Lunch “Research in Germany”, Sept 26, from 12h00 to 14h00. This session will bring together scientists and funding agencies from Germany to discuss research opportunities in that country. Limited availability. Learn more and complete your registration free of charge, here.

Special Sessions – Meet the Editors, Sept 27, from 12h00 to 14h00. The round table “Meet the editors” will host Paul Weiss (editor-in-chief of ACS Nano), Susan Sinnott (editor-in-chief of Computational Materials Science), Ifor Samuel (editor-in-chief of Synthetic Metals) and Tim Smith (IOP Publishing director) who will discuss scientific publication. Limited availability. Free registration in the registration form of the meeting, where activities can be selected. 

Special Sessions – Materials Research and Innovation, Sept 28, from 12h00 to 14h00. This panel will bring together representatives of Mahle, Braskem and Inova-Unicamp, who will present cases of university-industry collaboration for R&D in Brazil and discuss the role of materials research in innovation. Limited availability. Free registration in the registration form of the meeting, where activities can be selected. 

Tutorials: Two tutorials will be offered on Sept 25 from 14h00 to 17h00 to those registered at the event, at no extra cost. One tutorial is on computer simulations of atomic systems using Reactive Force Fields (theory and practice). The second, organized by Professor Valtencir Zucolotto, will address the capabilities required to make high-impact science, including scientific writing. Free registration in the registration form of the meeting, where activities can be selected. 

Publication of contributions: The papers presented at the XV Brazil-MRS Meeting may be submitted by their authors for peer review for publication in IOP scientific journals. More info.

Plenary sessions:  View the abstracts of the plenary lectures and the memorial lecture of our event and bios of the scientists presenting them. Here.

Exhibition: It will comprise 43 stands.

Accommodation and tickets: See the list of the travel agency “Follow Up” with hotels, hostels, guesthouses and the forms to book flights. Here. 

Vacation packages: The Follow Up website also suggests tour packages for before and after the event. Here.

Venue: See video of the city of Campinas and folder about the Expo Dom Pedro convention center. 

Organizers: This edition of the event is coordinated by Prof. Ana Flávia Nogueira (Unicamp, Institute of Chemistry) and Prof. Mônica Alonso Cotta (Unicamp, “Gleb Wataghin” Institute of Physics). See who are the members of the local committee and view the photos of the organizers. Here.

SBPMat news
SBPMat is pleased to announce that the XVI SBPMat/ Brazil-MRS Meeting will be held in Gramado (RS) from 24 to 28 10 to 14 September 2017.
Featured paper 

A study developed in Brazil by means of computer simulations showed that a defect in two-dimensional bismuth nanoribbon atom network generates conductive states in regions of the nanoribbons that should be in an insulating state. This work contributes to the study of a class of recently discovered materials, the topological insulators, and it was published in the scientific journal Nano Letters. See our story about the paper. 

People in the Materials Community
Professor Victor Carlos Pandolfelli (DEMa-UFSCar) was chosen to serve as one of the editors-in-chief of the journal Ceramics International (Elsevier). More.
Interviews with plenary speakers of the XV Brazil-MRS Meeting
Imagine yourself inserting in a computer the material properties you desire for a specific application and obtaining the project of the most appropriate material. This is a promise of Computational Materials Science, and it will be addressed by Prof. Susan Sinnott in a plenary lecture of the XV Brazil-MRS Meeting. Sinnott is Professor and Director of the Department of Materials Science and Engineering at Pennsylvania State University (USA) and editor-in-chief of the journal Computational Materials Science. Her scientific production, with more than 10,000 citations, includes important contributions to the development of simulation tools for heterogeneous material systems at the atomic scale. See our interview with the scientist. 

 

Reading tips

Research carried out with the participation of Brazilian scientists advances in the understanding of magnetic noise, which generates imperfections in magnetic materials applications (based on paper of Physical Review Letters). Here.

Events
  • XV Brazil-MRS Meeting (XV Encontro da SBPMat). Campinas, SP (Brazil). September, 25 to 29, 2016. Site. 
  • Aerospace Technology 2016. Stockholm (Sweden). October, 11 to 12, 2016. Site.
  • AutoOrg 2016. 5th Meeting on self-assembly structures in solutions and at interfaces. Florianópolis, SC (Brazil). November, 2 to 4, 2016. Site. 
  • I Simpósio Nacional de Nanobiotecnologia; II Workshop de Nanobiotecnologia da UFMG – Avanços & Aplicações. Belo Horizonte, MG (Brazil). December, 1 to 2, 2016. Site.

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Featured paper: Isolating nanoribbons with conducting regions.


[Paper: Topologically Protected Metallic States Induced by a One-Dimensional Extended Defect in the Bulk of a 2D Topological Insulator. Erika N. Lima, Tome M. Schmidt, and Ricardo W. Nunes. Nano Lett., 2016, 16 (7), pp 4025–4031. DOI: 10.1021/acs.nanolett.6b00521]

Isolating nanoribbons with conducting regions

A research carried out in Brazil made an important contribution to the study of topological insulators, a class of materials that was theoretically predicted in 2005 and experimentally confirmed in 2007. The study was reported in an article recently published  in Nano Letters (impact factor: 13.779).

A unique property of Topological insulators is that they behave as insulators on the inside and as conductors on its surface or edge. According to Ricardo Wagner Nunes, professor at the Federal University of Minas Gerais (UFMG) and corresponding author of the article, “non-topological insulators may also have conductive surfaces, but in the case of topological insulators, conduction of charge and spin on the surface is robust, as it is “protected” by time reversal symmetry”.

In the article in Nano Letters, Professor Nunes and colleagues, Erika Lima, of the Federal University of Mato Grosso (UFMT) – Rondonópolis campus, and Tome Schmidt, of the Federal University of Uberlândia (UFU), reported their work on a two-dimensional topological insulator, a bismuth nanoribbon of only two layers of bismuth atoms (one-atom thick), superimposed and bonded. Using computational methods, the scientists showed that the interior of the bismuth nanoribbon, instead of being fully insulating, may have conductive states (also called metallic states) generated from a particular type of irregularity in the atomic structure of the material, known as 558 extended defect.

Representation of bismuth bilayer nanoribbon with the defect 558, top view (left) and side view (right). The green balls represent the atoms of the top layer of the material and the blue balls, the atoms of the lower layer. In the center of the left figure, the defect is clearly seen: pentagons and an octagon stop the repetition of the hexagons.

 

“In our work, we show that a linear defect within a two-dimensional topological insulator can generate one-dimensional electronic quantum states that conduct spin and charge within the material”, say the authors.

This conclusion was supported through calculations performed on supercomputers, simulating what would happen to the electrons in quantum states, in the material, in the presence of defects. “We used first-principles Density Functional Theory calculations”, specify the authors, who relate that the computer simulation of defects in bismuth nanostructures required approximately 400 hours of computer simulations on supercomputers in the Department of Physics – UFMG and at the National Center for High Performance Computing in São Paulo (Cenapad) – UNICAMP.

A figura mostra a curva de dispersão dos estados topológicos metálicos, localizados no defeito 558, marcados em azul e vermelho.
The figure shows, marked in blue and red, the dispersion curve of the metal topological states located in the defect 558.

In the article, the authors also propose the existence of pentaoctite, a new two-dimensional topological insulator. This material, which has not been synthesized yet, is a bismuth bilayer with a crystal lattice formed by atoms arranged in pentagons and octagons. As stated by the authors, “In our calculations we show that this new “phase” of the two-dimensional bismuth has low formation energy, which opens the possibility to be synthesized in the laboratory”.

According to the authors, the work reported in Nano Letters raises several issues in the scope of fundamental research, such as the influence of magnetic and non-magnetic impurities on the spin and charge transport in the proposed topological states, and the connection between the network symmetries and nature of the topological edge states on pentaoctite. “From the point of view of applications, it would be interesting if our work could motivate experimental studies of two-dimensional topological insulators based on bismuth and other materials, enabling theoretical and experimental collaboration on this issue”, comment the authors, leaving an open invitation to experimental research groups.

The origin of this research work

“The work originated by combining my interest in extended topological defects in two-dimensional and three-dimensional materials, with the experience of Professor Tome Mauro Schmidt (UFU) and Erika Lima, his doctoral student in the subject of topological insulators”, states Nunes.

In 2012, Nunes and collaborators published an article in Nano Letters on magnetic states (non topological) generated by linear extended defects in a monolayer of graphene. Later, in a conversation with Schmidt, a collaboration was decided in order to investigate if an extended defect with the same morphology would lead to the formation of topological states in a bidimensional topological insulator made of bismuth.

In her post-doctorate in the group of Professor Nunes, in 2015, Erika Lima performed all computer calculations. The three researchers, who are the authors of the article, interpreted the results and wrote the paper.

The research that led to the article received funding from Brazilian agencies CAPES, CNPq, FAPEMIG and from the National Institute of Science and Technology on Carbon Nanomaterials.

autores
Photos of the authors. From left to right, Erika Lima, currently a professor at UFMT, Tome Schmidt, professor at UFU, and Ricardo Nunes, professor at UFMG.