http://scholar.google.com/citations?hl=en&user=95SvbM8AAAAJ
1.
Rurali, R; Cartoixa, X; Galvao, DS
Large electromechanical response in silicon nanowires predicted from first-principles electronic structure calculations Journal Article
Em: Physical Review B, vol. 77, não 7, pp. 073403, 2008.
@article{rurali2008large,
title = {Large electromechanical response in silicon nanowires predicted from first-principles electronic structure calculations},
author = {Rurali, R and Cartoixa, X and Galvao, DS},
url = {http://journals.aps.org/prb/abstract/10.1103/PhysRevB.77.073403},
year = {2008},
date = {2008-01-01},
journal = {Physical Review B},
volume = {77},
number = {7},
pages = {073403},
publisher = {American Physical Society},
abstract = {We study by means of first-principles electronic structure calculations the electromechanical response, i.e., the structural modifications upon charge injection, of ⟨100⟩ silicon nanowires. We show that, at variance with sp2 carbon nanostructures, the response is remarkably linear, discriminates between injected charge of different signs, and is up to one order of magnitude larger than in carbon nanotubes.
},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We study by means of first-principles electronic structure calculations the electromechanical response, i.e., the structural modifications upon charge injection, of ⟨100⟩ silicon nanowires. We show that, at variance with sp2 carbon nanostructures, the response is remarkably linear, discriminates between injected charge of different signs, and is up to one order of magnitude larger than in carbon nanotubes.
2.
Fonseca, AD; Malta, CP; Galvao, DS
Elastic Properties of Normal and Binormal Helical Nanowires Proceedings
Warrendale, Pa.; Materials Research Society; 1999, vol. 963, 2007.
@proceedings{fonseca2007elastic,
title = {Elastic Properties of Normal and Binormal Helical Nanowires},
author = {Fonseca, AD and Malta, CP and Galvao, DS},
url = {http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8026852},
year = {2007},
date = {2007-01-01},
journal = {MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS},
volume = {963},
pages = {88},
publisher = {Warrendale, Pa.; Materials Research Society; 1999},
abstract = {A helical nanowire can be defined as being a nanoscopic rod whose axis follows a helical curve in space. In the case of a nanowire with asymmetric cross section, the helical nanostructure can be classified as normal or binormal helix, according to the orientation of the cross section with respect to the helical axis of the structure. In this work, we present a simple model to study the elastic properties of a helical nanowire with asymmetric cross section. We use the framework of the Kirchhoff rod model to obtain an expression relating the Hooke's constant, h, of normal and binormal nanohelices to their geometric features. We also obtain the Young's modulus values. These relations can be used by experimentalists to evaluate the elastic properties of helical nanostructures. We showed that the Hooke's constant of a normal nanohelix is higher than that of a binormal one. We illustrate our results using experimentally obtained nanohelices reported in the literature.},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
}
A helical nanowire can be defined as being a nanoscopic rod whose axis follows a helical curve in space. In the case of a nanowire with asymmetric cross section, the helical nanostructure can be classified as normal or binormal helix, according to the orientation of the cross section with respect to the helical axis of the structure. In this work, we present a simple model to study the elastic properties of a helical nanowire with asymmetric cross section. We use the framework of the Kirchhoff rod model to obtain an expression relating the Hooke's constant, h, of normal and binormal nanohelices to their geometric features. We also obtain the Young's modulus values. These relations can be used by experimentalists to evaluate the elastic properties of helical nanostructures. We showed that the Hooke's constant of a normal nanohelix is higher than that of a binormal one. We illustrate our results using experimentally obtained nanohelices reported in the literature.
3.
Fonseca, Alexandre F; Malta, CP; Galvao, DS
Is it possible to grow amorphous normal nanosprings? Journal Article
Em: Nanotechnology, vol. 18, não 43, pp. 435606, 2007.
@article{fonseca2007possible,
title = {Is it possible to grow amorphous normal nanosprings?},
author = {Fonseca, Alexandre F and Malta, CP and Galvao, DS},
url = {http://iopscience.iop.org/0957-4484/18/43/435606},
year = {2007},
date = {2007-01-01},
journal = {Nanotechnology},
volume = {18},
number = {43},
pages = {435606},
publisher = {IOP Publishing},
abstract = {Nanosprings have been objects of intense investigations in recent years. They can be classified as normal or binormal depending on the geometry of their cross-section. As normal amorphous nanosprings have not yet been observed experimentally, we have decided to investigate this matter. We discuss the shape of the catalyst in terms of the cross-sectional shape of the nanospring and show that, within the vapor–liquid–solid model, the growth of amorphous binormal nanosprings is energetically favored.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Nanosprings have been objects of intense investigations in recent years. They can be classified as normal or binormal depending on the geometry of their cross-section. As normal amorphous nanosprings have not yet been observed experimentally, we have decided to investigate this matter. We discuss the shape of the catalyst in terms of the cross-sectional shape of the nanospring and show that, within the vapor–liquid–solid model, the growth of amorphous binormal nanosprings is energetically favored.
4.
da Fonseca, Alexandre F; Malta, CP; Galvao, Douglas S
Elastic properties of nanowires Journal Article
Em: Journal of Applied Physics, vol. 99, não 9, pp. 094310, 2006.
@article{da2006elastic,
title = {Elastic properties of nanowires},
author = {da Fonseca, Alexandre F and Malta, CP and Galvao, Douglas S},
url = {http://scitation.aip.org/content/aip/journal/jap/99/9/10.1063/1.2194309},
year = {2006},
date = {2006-01-01},
journal = {Journal of Applied Physics},
volume = {99},
number = {9},
pages = {094310},
publisher = {AIP Publishing},
abstract = {We present a model to study Young’s modulus and Poisson’s ratio of the composite material of amorphous nanowires. It is an extension of the model derived by two of us [da Fonseca and Galvão, Phys. Rev. Lett.92, 175502 (2004)] to study the elastic properties of amorphous nanosprings. The model is based on twisting and tensioning a straight nanowire and we propose an experimental setup to obtain the elastic parameters of the nanowire. We used the Kirchhoff rod model to obtain the expressions for the elastic constants of the nanowire.
},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We present a model to study Young’s modulus and Poisson’s ratio of the composite material of amorphous nanowires. It is an extension of the model derived by two of us [da Fonseca and Galvão, Phys. Rev. Lett.92, 175502 (2004)] to study the elastic properties of amorphous nanosprings. The model is based on twisting and tensioning a straight nanowire and we propose an experimental setup to obtain the elastic parameters of the nanowire. We used the Kirchhoff rod model to obtain the expressions for the elastic constants of the nanowire.
5.
da Fonseca, Alexandre F; Malta, CP; Galvao, DS
Mechanical properties of amorphous nanosprings Journal Article
Em: Nanotechnology, vol. 17, não 22, pp. 5620, 2006.
@article{da2006mechanical,
title = {Mechanical properties of amorphous nanosprings},
author = {da Fonseca, Alexandre F and Malta, CP and Galvao, DS},
url = {http://iopscience.iop.org/0957-4484/17/22/015},
year = {2006},
date = {2006-01-01},
journal = {Nanotechnology},
volume = {17},
number = {22},
pages = {5620},
publisher = {IOP Publishing},
abstract = {Helical amorphous nanosprings have attracted particular interest due to their special mechanical properties. In this work we present a simple model, within the framework of the Kirchhoff rod model, for investigating the structural properties of nanosprings having asymmetric cross section. We have derived expressions that can be used to obtain the Young's modulus and Poisson's ratio of the nanospring material composite. We also address the importance of the presence of a catalyst in the growth process of amorphous nanosprings in terms of the stability of helical rods.
},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Helical amorphous nanosprings have attracted particular interest due to their special mechanical properties. In this work we present a simple model, within the framework of the Kirchhoff rod model, for investigating the structural properties of nanosprings having asymmetric cross section. We have derived expressions that can be used to obtain the Young's modulus and Poisson's ratio of the nanospring material composite. We also address the importance of the presence of a catalyst in the growth process of amorphous nanosprings in terms of the stability of helical rods.
6.
da Fonseca, Alexandre F; Galvao, Douglas S; Malta, Coraci P
Binormal nanohelices Proceedings
Cambridge University Press, vol. 903, 2005.
@proceedings{da2005binormal,
title = {Binormal nanohelices},
author = {da Fonseca, Alexandre F and Galvao, Douglas S and Malta, Coraci P},
url = {http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8108794&fileId=S1946427400047680},
year = {2005},
date = {2005-01-01},
journal = {MRS Proceedings},
volume = {903},
pages = {0903--Z14},
publisher = {Cambridge University Press},
abstract = {Helical structures can be classified in accordance with the orientation of its cross-section with respect to the normal or binormal vectors. We investigate the geometric features of several nanosprings verifying the non-existence of normal nanohelices. In this work, using the VLS growth model, we explain not only the absence of normal nanosprings but also the growing process of binormal nanosprings. The dynamical stability of crystalline ZnO binormal nanohelices is also addressed.},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
}
Helical structures can be classified in accordance with the orientation of its cross-section with respect to the normal or binormal vectors. We investigate the geometric features of several nanosprings verifying the non-existence of normal nanohelices. In this work, using the VLS growth model, we explain not only the absence of normal nanosprings but also the growing process of binormal nanosprings. The dynamical stability of crystalline ZnO binormal nanohelices is also addressed.
7.
da Fonseca, Alexandre F; Galvao, Douglas S
Mechanical properties of nanosprings Journal Article
Em: Physical review letters, vol. 92, não 17, pp. 175502, 2004.
@article{da2004mechanical,
title = {Mechanical properties of nanosprings},
author = {da Fonseca, Alexandre F and Galvao, Douglas S},
url = {http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.92.175502},
year = {2004},
date = {2004-01-01},
journal = {Physical review letters},
volume = {92},
number = {17},
pages = {175502},
publisher = {APS},
abstract = {Nanostructures (nanotubes, nanowires, etc.) have been the object of intense theoretical and experimental investigations in recent years. Among these structures, helical nanosprings or nanocoils have attracted particular interest due to their special mechanical properties. In this work, we investigated structural properties of nanosprings in the Kirchhoff rod model. We derived expressions that can be used experimentally to obtain nanospring Young’s modulus and Poisson’s ratio values. Our results also might explain why the presence of catalytic particles is so important in nanostructure growth.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Nanostructures (nanotubes, nanowires, etc.) have been the object of intense theoretical and experimental investigations in recent years. Among these structures, helical nanosprings or nanocoils have attracted particular interest due to their special mechanical properties. In this work, we investigated structural properties of nanosprings in the Kirchhoff rod model. We derived expressions that can be used experimentally to obtain nanospring Young’s modulus and Poisson’s ratio values. Our results also might explain why the presence of catalytic particles is so important in nanostructure growth.
2008
7.
Rurali, R; Cartoixa, X; Galvao, DS
Large electromechanical response in silicon nanowires predicted from first-principles electronic structure calculations Journal Article
Em: Physical Review B, vol. 77, não 7, pp. 073403, 2008.
Resumo | Links | BibTeX | Tags: DFT, Eletroactuation, Nanowires, Silicon
@article{rurali2008large,
title = {Large electromechanical response in silicon nanowires predicted from first-principles electronic structure calculations},
author = {Rurali, R and Cartoixa, X and Galvao, DS},
url = {http://journals.aps.org/prb/abstract/10.1103/PhysRevB.77.073403},
year = {2008},
date = {2008-01-01},
journal = {Physical Review B},
volume = {77},
number = {7},
pages = {073403},
publisher = {American Physical Society},
abstract = {We study by means of first-principles electronic structure calculations the electromechanical response, i.e., the structural modifications upon charge injection, of ⟨100⟩ silicon nanowires. We show that, at variance with sp2 carbon nanostructures, the response is remarkably linear, discriminates between injected charge of different signs, and is up to one order of magnitude larger than in carbon nanotubes.
},
keywords = {DFT, Eletroactuation, Nanowires, Silicon},
pubstate = {published},
tppubtype = {article}
}
We study by means of first-principles electronic structure calculations the electromechanical response, i.e., the structural modifications upon charge injection, of ⟨100⟩ silicon nanowires. We show that, at variance with sp2 carbon nanostructures, the response is remarkably linear, discriminates between injected charge of different signs, and is up to one order of magnitude larger than in carbon nanotubes.
2007
6.
Fonseca, AD; Malta, CP; Galvao, DS
Elastic Properties of Normal and Binormal Helical Nanowires Proceedings
Warrendale, Pa.; Materials Research Society; 1999, vol. 963, 2007.
Resumo | Links | BibTeX | Tags: Elasticity, Helical Structures, Mechanical Properties, Nanowires
@proceedings{fonseca2007elastic,
title = {Elastic Properties of Normal and Binormal Helical Nanowires},
author = {Fonseca, AD and Malta, CP and Galvao, DS},
url = {http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8026852},
year = {2007},
date = {2007-01-01},
journal = {MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS},
volume = {963},
pages = {88},
publisher = {Warrendale, Pa.; Materials Research Society; 1999},
abstract = {A helical nanowire can be defined as being a nanoscopic rod whose axis follows a helical curve in space. In the case of a nanowire with asymmetric cross section, the helical nanostructure can be classified as normal or binormal helix, according to the orientation of the cross section with respect to the helical axis of the structure. In this work, we present a simple model to study the elastic properties of a helical nanowire with asymmetric cross section. We use the framework of the Kirchhoff rod model to obtain an expression relating the Hooke's constant, h, of normal and binormal nanohelices to their geometric features. We also obtain the Young's modulus values. These relations can be used by experimentalists to evaluate the elastic properties of helical nanostructures. We showed that the Hooke's constant of a normal nanohelix is higher than that of a binormal one. We illustrate our results using experimentally obtained nanohelices reported in the literature.},
keywords = {Elasticity, Helical Structures, Mechanical Properties, Nanowires},
pubstate = {published},
tppubtype = {proceedings}
}
A helical nanowire can be defined as being a nanoscopic rod whose axis follows a helical curve in space. In the case of a nanowire with asymmetric cross section, the helical nanostructure can be classified as normal or binormal helix, according to the orientation of the cross section with respect to the helical axis of the structure. In this work, we present a simple model to study the elastic properties of a helical nanowire with asymmetric cross section. We use the framework of the Kirchhoff rod model to obtain an expression relating the Hooke's constant, h, of normal and binormal nanohelices to their geometric features. We also obtain the Young's modulus values. These relations can be used by experimentalists to evaluate the elastic properties of helical nanostructures. We showed that the Hooke's constant of a normal nanohelix is higher than that of a binormal one. We illustrate our results using experimentally obtained nanohelices reported in the literature.
5.
Fonseca, Alexandre F; Malta, CP; Galvao, DS
Is it possible to grow amorphous normal nanosprings? Journal Article
Em: Nanotechnology, vol. 18, não 43, pp. 435606, 2007.
Resumo | Links | BibTeX | Tags: Elasticity, Helical Structures, Mechanical Properties, Nanowires
@article{fonseca2007possible,
title = {Is it possible to grow amorphous normal nanosprings?},
author = {Fonseca, Alexandre F and Malta, CP and Galvao, DS},
url = {http://iopscience.iop.org/0957-4484/18/43/435606},
year = {2007},
date = {2007-01-01},
journal = {Nanotechnology},
volume = {18},
number = {43},
pages = {435606},
publisher = {IOP Publishing},
abstract = {Nanosprings have been objects of intense investigations in recent years. They can be classified as normal or binormal depending on the geometry of their cross-section. As normal amorphous nanosprings have not yet been observed experimentally, we have decided to investigate this matter. We discuss the shape of the catalyst in terms of the cross-sectional shape of the nanospring and show that, within the vapor–liquid–solid model, the growth of amorphous binormal nanosprings is energetically favored.},
keywords = {Elasticity, Helical Structures, Mechanical Properties, Nanowires},
pubstate = {published},
tppubtype = {article}
}
Nanosprings have been objects of intense investigations in recent years. They can be classified as normal or binormal depending on the geometry of their cross-section. As normal amorphous nanosprings have not yet been observed experimentally, we have decided to investigate this matter. We discuss the shape of the catalyst in terms of the cross-sectional shape of the nanospring and show that, within the vapor–liquid–solid model, the growth of amorphous binormal nanosprings is energetically favored.
2006
4.
da Fonseca, Alexandre F; Malta, CP; Galvao, Douglas S
Elastic properties of nanowires Journal Article
Em: Journal of Applied Physics, vol. 99, não 9, pp. 094310, 2006.
Resumo | Links | BibTeX | Tags: Elasticity, Filaments, Nanowires
@article{da2006elastic,
title = {Elastic properties of nanowires},
author = {da Fonseca, Alexandre F and Malta, CP and Galvao, Douglas S},
url = {http://scitation.aip.org/content/aip/journal/jap/99/9/10.1063/1.2194309},
year = {2006},
date = {2006-01-01},
journal = {Journal of Applied Physics},
volume = {99},
number = {9},
pages = {094310},
publisher = {AIP Publishing},
abstract = {We present a model to study Young’s modulus and Poisson’s ratio of the composite material of amorphous nanowires. It is an extension of the model derived by two of us [da Fonseca and Galvão, Phys. Rev. Lett.92, 175502 (2004)] to study the elastic properties of amorphous nanosprings. The model is based on twisting and tensioning a straight nanowire and we propose an experimental setup to obtain the elastic parameters of the nanowire. We used the Kirchhoff rod model to obtain the expressions for the elastic constants of the nanowire.
},
keywords = {Elasticity, Filaments, Nanowires},
pubstate = {published},
tppubtype = {article}
}
We present a model to study Young’s modulus and Poisson’s ratio of the composite material of amorphous nanowires. It is an extension of the model derived by two of us [da Fonseca and Galvão, Phys. Rev. Lett.92, 175502 (2004)] to study the elastic properties of amorphous nanosprings. The model is based on twisting and tensioning a straight nanowire and we propose an experimental setup to obtain the elastic parameters of the nanowire. We used the Kirchhoff rod model to obtain the expressions for the elastic constants of the nanowire.
3.
da Fonseca, Alexandre F; Malta, CP; Galvao, DS
Mechanical properties of amorphous nanosprings Journal Article
Em: Nanotechnology, vol. 17, não 22, pp. 5620, 2006.
Resumo | Links | BibTeX | Tags: Elasticity, Filaments, Nanowires
@article{da2006mechanical,
title = {Mechanical properties of amorphous nanosprings},
author = {da Fonseca, Alexandre F and Malta, CP and Galvao, DS},
url = {http://iopscience.iop.org/0957-4484/17/22/015},
year = {2006},
date = {2006-01-01},
journal = {Nanotechnology},
volume = {17},
number = {22},
pages = {5620},
publisher = {IOP Publishing},
abstract = {Helical amorphous nanosprings have attracted particular interest due to their special mechanical properties. In this work we present a simple model, within the framework of the Kirchhoff rod model, for investigating the structural properties of nanosprings having asymmetric cross section. We have derived expressions that can be used to obtain the Young's modulus and Poisson's ratio of the nanospring material composite. We also address the importance of the presence of a catalyst in the growth process of amorphous nanosprings in terms of the stability of helical rods.
},
keywords = {Elasticity, Filaments, Nanowires},
pubstate = {published},
tppubtype = {article}
}
Helical amorphous nanosprings have attracted particular interest due to their special mechanical properties. In this work we present a simple model, within the framework of the Kirchhoff rod model, for investigating the structural properties of nanosprings having asymmetric cross section. We have derived expressions that can be used to obtain the Young's modulus and Poisson's ratio of the nanospring material composite. We also address the importance of the presence of a catalyst in the growth process of amorphous nanosprings in terms of the stability of helical rods.
2005
2.
da Fonseca, Alexandre F; Galvao, Douglas S; Malta, Coraci P
Binormal nanohelices Proceedings
Cambridge University Press, vol. 903, 2005.
Resumo | Links | BibTeX | Tags: Elasticity, Filaments, Nanowires
@proceedings{da2005binormal,
title = {Binormal nanohelices},
author = {da Fonseca, Alexandre F and Galvao, Douglas S and Malta, Coraci P},
url = {http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8108794&fileId=S1946427400047680},
year = {2005},
date = {2005-01-01},
journal = {MRS Proceedings},
volume = {903},
pages = {0903--Z14},
publisher = {Cambridge University Press},
abstract = {Helical structures can be classified in accordance with the orientation of its cross-section with respect to the normal or binormal vectors. We investigate the geometric features of several nanosprings verifying the non-existence of normal nanohelices. In this work, using the VLS growth model, we explain not only the absence of normal nanosprings but also the growing process of binormal nanosprings. The dynamical stability of crystalline ZnO binormal nanohelices is also addressed.},
keywords = {Elasticity, Filaments, Nanowires},
pubstate = {published},
tppubtype = {proceedings}
}
Helical structures can be classified in accordance with the orientation of its cross-section with respect to the normal or binormal vectors. We investigate the geometric features of several nanosprings verifying the non-existence of normal nanohelices. In this work, using the VLS growth model, we explain not only the absence of normal nanosprings but also the growing process of binormal nanosprings. The dynamical stability of crystalline ZnO binormal nanohelices is also addressed.
2004
1.
da Fonseca, Alexandre F; Galvao, Douglas S
Mechanical properties of nanosprings Journal Article
Em: Physical review letters, vol. 92, não 17, pp. 175502, 2004.
Resumo | Links | BibTeX | Tags: Elasticity, Filaments, Nanowires
@article{da2004mechanical,
title = {Mechanical properties of nanosprings},
author = {da Fonseca, Alexandre F and Galvao, Douglas S},
url = {http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.92.175502},
year = {2004},
date = {2004-01-01},
journal = {Physical review letters},
volume = {92},
number = {17},
pages = {175502},
publisher = {APS},
abstract = {Nanostructures (nanotubes, nanowires, etc.) have been the object of intense theoretical and experimental investigations in recent years. Among these structures, helical nanosprings or nanocoils have attracted particular interest due to their special mechanical properties. In this work, we investigated structural properties of nanosprings in the Kirchhoff rod model. We derived expressions that can be used experimentally to obtain nanospring Young’s modulus and Poisson’s ratio values. Our results also might explain why the presence of catalytic particles is so important in nanostructure growth.},
keywords = {Elasticity, Filaments, Nanowires},
pubstate = {published},
tppubtype = {article}
}
Nanostructures (nanotubes, nanowires, etc.) have been the object of intense theoretical and experimental investigations in recent years. Among these structures, helical nanosprings or nanocoils have attracted particular interest due to their special mechanical properties. In this work, we investigated structural properties of nanosprings in the Kirchhoff rod model. We derived expressions that can be used experimentally to obtain nanospring Young’s modulus and Poisson’s ratio values. Our results also might explain why the presence of catalytic particles is so important in nanostructure growth.
