1.
E. Perim T. Botari, P. A. S. Autreto
Mechanical properties and fracture dynamics of silicene membranes Journal Article
Em: Phys. Chem. Chem. Phys., vol. 16, pp. 19417–19423, 2014.
@article{t2014mechanical,
title = {Mechanical properties and fracture dynamics of silicene membranes},
author = {T. Botari, E. Perim, P. A. S. Autreto, A. C. T. van Duin, R. Paupitz, D. S. Galvao},
url = {http://pubs.rsc.org/en/Content/ArticleLanding/2014/CP/C4CP02902J#!divAbstract},
year = {2014},
date = {2014-01-01},
journal = {Phys. Chem. Chem. Phys.},
volume = {16},
pages = {19417--19423},
abstract = {As graphene has become one of the most important materials, there is renewed interest in other similar structures. One example is silicene, the silicon analogue of graphene. It shares some of the remarkable graphene properties, such as the Dirac cone, but presents some distinct ones, such as a pronounced structural buckling. We have investigated, through density functional based tight-binding (DFTB), as well as reactive molecular dynamics (using ReaxFF), the mechanical properties of suspended single-layer silicene. We calculated the elastic constants, analyzed the fracture patterns and edge reconstructions. We also addressed the stress distributions, unbuckling mechanisms and the fracture dependence on the temperature. We analysed the differences due to distinct edge morphologies, namely zigzag and armchair.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
As graphene has become one of the most important materials, there is renewed interest in other similar structures. One example is silicene, the silicon analogue of graphene. It shares some of the remarkable graphene properties, such as the Dirac cone, but presents some distinct ones, such as a pronounced structural buckling. We have investigated, through density functional based tight-binding (DFTB), as well as reactive molecular dynamics (using ReaxFF), the mechanical properties of suspended single-layer silicene. We calculated the elastic constants, analyzed the fracture patterns and edge reconstructions. We also addressed the stress distributions, unbuckling mechanisms and the fracture dependence on the temperature. We analysed the differences due to distinct edge morphologies, namely zigzag and armchair.
2.
Pedro A Autreto Ricardo P dos Santos, Eric Perim
On the Unzipping Mechanisms of Carbon Nanotubes: Insights from Reactive Molecular Dynamics Simulations Conferência
On the Unzipping Mechanisms of Carbon Nanotubes: Insights from Reactive Molecular Dynamics Simulations, não DD1.4, MRSSpring 2012, 2012.
@conference{2012MRSSpring-DD,
title = {On the Unzipping Mechanisms of Carbon Nanotubes: Insights from Reactive Molecular Dynamics Simulations},
author = {Ricardo P dos Santos, Pedro A Autreto, Eric Perim, Gustavo Brunetto, Douglas S Galvao},
url = {http://www.mrs.org/s12-program-dd/
https://sites.ifi.unicamp.br/autretos/files/2015/04/2012MRSSpringMeeting-DD-Program-Symposium-D-Nanocontacts–Emerging-Materials-and-Processing-for-Ohmicity-and-Rectification-2012-MRS-Spring-Meeting.pdf},
year = {2012},
date = {2012-04-09},
booktitle = {On the Unzipping Mechanisms of Carbon Nanotubes: Insights from Reactive Molecular Dynamics Simulations},
number = {DD1.4},
publisher = {MRSSpring 2012},
abstract = {Graphene has been one of the hottest topics in materials science today. Due to its unique and unusual electronic properties graphene is been considered one of the most promising materials for the basis of a new nanoelectronics. However, in its pristine form graphene is a zero-gap semiconductor. This poses serious limitations to its use in some kind of electronic applications (some kind of transistors). In order to create non-zero graphene-like structures many approaches have been tried, such as, hydrogenation, fluorination and/or other chemical and physical functionalizations, with limited success. It has also been shown that making thin graphene stripes, the so-called graphene nanoribbons (GNRs), it is possible to create non-zero structures with some control of the process. But large scale and controlled GNR synthesis has been proved to be very difficult. Another possibility of producing GNR in a more controllable way is through cutting (unzipping) carbon nanotubes (CNTs). This has been achieved with different chemical [1] and physical [2] approaches. However, in spite of many experimental and theoretical studies on this problem, some important aspects remain to be fully understood. In this work we investigated the process of CNT fracture (unzipping) through molecular dynamics simulations using reactive force fields (ReaxFF), as implemented in the LAMMPS code. We considered multi-walled CNTs of different dimensions and chiralities and under mechanical stretching. Our results show that the unzipping mechanisms are highly dependent on CNT chirality. Well defined and distinct fracture patterns were observed for different chiralities. Zig-zag CNTs favor the creation of GNRs with well defined armchair edges, while armchair and chiral CNTs produde GNRs with less defined (defective) edges. The reasons why almost perfect linear CNT cuts are so frequently observed are also addressed. [1] D. V. Kosynkin et al., Nature v458, 872 (2009). [2] L. Jiao et al, Nature v458, 877 (2009).},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Graphene has been one of the hottest topics in materials science today. Due to its unique and unusual electronic properties graphene is been considered one of the most promising materials for the basis of a new nanoelectronics. However, in its pristine form graphene is a zero-gap semiconductor. This poses serious limitations to its use in some kind of electronic applications (some kind of transistors). In order to create non-zero graphene-like structures many approaches have been tried, such as, hydrogenation, fluorination and/or other chemical and physical functionalizations, with limited success. It has also been shown that making thin graphene stripes, the so-called graphene nanoribbons (GNRs), it is possible to create non-zero structures with some control of the process. But large scale and controlled GNR synthesis has been proved to be very difficult. Another possibility of producing GNR in a more controllable way is through cutting (unzipping) carbon nanotubes (CNTs). This has been achieved with different chemical [1] and physical [2] approaches. However, in spite of many experimental and theoretical studies on this problem, some important aspects remain to be fully understood. In this work we investigated the process of CNT fracture (unzipping) through molecular dynamics simulations using reactive force fields (ReaxFF), as implemented in the LAMMPS code. We considered multi-walled CNTs of different dimensions and chiralities and under mechanical stretching. Our results show that the unzipping mechanisms are highly dependent on CNT chirality. Well defined and distinct fracture patterns were observed for different chiralities. Zig-zag CNTs favor the creation of GNRs with well defined armchair edges, while armchair and chiral CNTs produde GNRs with less defined (defective) edges. The reasons why almost perfect linear CNT cuts are so frequently observed are also addressed. [1] D. V. Kosynkin et al., Nature v458, 872 (2009). [2] L. Jiao et al, Nature v458, 877 (2009).
2014
1.
E. Perim T. Botari, P. A. S. Autreto
Mechanical properties and fracture dynamics of silicene membranes Journal Article
Em: Phys. Chem. Chem. Phys., vol. 16, pp. 19417–19423, 2014.
Resumo | Links | BibTeX | Tags: mechanical properties, molecular dynamics, silicene
@article{t2014mechanical,
title = {Mechanical properties and fracture dynamics of silicene membranes},
author = {T. Botari, E. Perim, P. A. S. Autreto, A. C. T. van Duin, R. Paupitz, D. S. Galvao},
url = {http://pubs.rsc.org/en/Content/ArticleLanding/2014/CP/C4CP02902J#!divAbstract},
year = {2014},
date = {2014-01-01},
journal = {Phys. Chem. Chem. Phys.},
volume = {16},
pages = {19417--19423},
abstract = {As graphene has become one of the most important materials, there is renewed interest in other similar structures. One example is silicene, the silicon analogue of graphene. It shares some of the remarkable graphene properties, such as the Dirac cone, but presents some distinct ones, such as a pronounced structural buckling. We have investigated, through density functional based tight-binding (DFTB), as well as reactive molecular dynamics (using ReaxFF), the mechanical properties of suspended single-layer silicene. We calculated the elastic constants, analyzed the fracture patterns and edge reconstructions. We also addressed the stress distributions, unbuckling mechanisms and the fracture dependence on the temperature. We analysed the differences due to distinct edge morphologies, namely zigzag and armchair.},
keywords = {mechanical properties, molecular dynamics, silicene},
pubstate = {published},
tppubtype = {article}
}
As graphene has become one of the most important materials, there is renewed interest in other similar structures. One example is silicene, the silicon analogue of graphene. It shares some of the remarkable graphene properties, such as the Dirac cone, but presents some distinct ones, such as a pronounced structural buckling. We have investigated, through density functional based tight-binding (DFTB), as well as reactive molecular dynamics (using ReaxFF), the mechanical properties of suspended single-layer silicene. We calculated the elastic constants, analyzed the fracture patterns and edge reconstructions. We also addressed the stress distributions, unbuckling mechanisms and the fracture dependence on the temperature. We analysed the differences due to distinct edge morphologies, namely zigzag and armchair.
