Geoffroy Prévot - Academia.edu (original) (raw)

Papers by Geoffroy Prévot

The Journal of Physical Chemistry B, 2002

Journal of Applied Crystallography, 2007

It is demonstrated that grazing-incidence X-ray diffraction is a direct tool for measuring the el... more It is demonstrated that grazing-incidence X-ray diffraction is a direct tool for measuring the elastic displacement modes near the surface of a crystal. Due to the fact that X-ray diffraction is a Fourier transform of the electronic density, and thus, of the atomic positions, elastic displacement modes appear as additional spots in the reciprocal space. Their characteristics can be directly derived from the elastic constants of the material. Measuring the amplitude of the diffracted wave for these peaks allows direct determination of the force distribution at the surface, which is at the origin of the elastic displacements. Various examples of such determinations are given for self-organized surfaces and for vicinal surfaces. research papers J. Appl. Cryst. (2007). 40, 874-882 Geoffroy Prévot et al. Elastic displacement modes 875

Comptes Rendus Physique, 2005

Self-ordering at crystal surfaces has been the subject of intense efforts during the last ten yea... more Self-ordering at crystal surfaces has been the subject of intense efforts during the last ten years, since it has been recognized as a promising way for growing uniform nanostructures with regular sizes and spacings in the 1-100 nm range. In this article we give an overview of the self-organized nanostructures growth on spontaneously nano-patterned templates. A great variety of surfaces exhibits a nano-scale order at thermal equilibrium, including adsorbate-induced reconstruction, surface dislocations networks, vicinal surfaces or more complex systems. Continuum models have been proposed where long-range elastic interactions are responsible for spontaneous periodic domain formation. Today the comparison between experiments such as Grazing Incidence X-Ray Diffraction experiments and calculations has lead to a great improvement of our fundamental understanding of the physics of self-ordering at crystal surfaces. Then, epitaxial growth on self-ordered surfaces leads to nanostructures organized growth. The present knowledge of modelization of such an heterogeneous growth using multi-scaled calculations is discussed. Such a high quality of both long-range and local ordered growth opens up the possibility of making measurements of physical properties of such nanostructures by macroscopic integration techniques. To cite this article: S. Rousset et al., C. R. Physique 6 (2005).  2004 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Physical Review B, 2013

We report here in situ measurements of the evolution of the Ag(110) surface during Si growth, usi... more We report here in situ measurements of the evolution of the Ag(110) surface during Si growth, using scanning tunneling microscopy and grazing incidence x-ray diffraction. We provide compelling evidence of an Ag(110) surface reconstruction associated with the release of Ag atoms induced by the growth of Si nanoribbons. Our results are in agreement with a missing row reconstruction of the Ag layer underneath the nanoribbons. This challenges the current understanding of the Si growth on nonreconstructed Ag(110), interpreted within the framework of silicene models.

The Journal of Physical Chemistry B, 2002

Journal of Applied Crystallography, 2007

It is demonstrated that grazing-incidence X-ray diffraction is a direct tool for measuring the el... more It is demonstrated that grazing-incidence X-ray diffraction is a direct tool for measuring the elastic displacement modes near the surface of a crystal. Due to the fact that X-ray diffraction is a Fourier transform of the electronic density, and thus, of the atomic positions, elastic displacement modes appear as additional spots in the reciprocal space. Their characteristics can be directly derived from the elastic constants of the material. Measuring the amplitude of the diffracted wave for these peaks allows direct determination of the force distribution at the surface, which is at the origin of the elastic displacements. Various examples of such determinations are given for self-organized surfaces and for vicinal surfaces. research papers J. Appl. Cryst. (2007). 40, 874-882 Geoffroy Prévot et al. Elastic displacement modes 875

Comptes Rendus Physique, 2005

Self-ordering at crystal surfaces has been the subject of intense efforts during the last ten yea... more Self-ordering at crystal surfaces has been the subject of intense efforts during the last ten years, since it has been recognized as a promising way for growing uniform nanostructures with regular sizes and spacings in the 1-100 nm range. In this article we give an overview of the self-organized nanostructures growth on spontaneously nano-patterned templates. A great variety of surfaces exhibits a nano-scale order at thermal equilibrium, including adsorbate-induced reconstruction, surface dislocations networks, vicinal surfaces or more complex systems. Continuum models have been proposed where long-range elastic interactions are responsible for spontaneous periodic domain formation. Today the comparison between experiments such as Grazing Incidence X-Ray Diffraction experiments and calculations has lead to a great improvement of our fundamental understanding of the physics of self-ordering at crystal surfaces. Then, epitaxial growth on self-ordered surfaces leads to nanostructures organized growth. The present knowledge of modelization of such an heterogeneous growth using multi-scaled calculations is discussed. Such a high quality of both long-range and local ordered growth opens up the possibility of making measurements of physical properties of such nanostructures by macroscopic integration techniques. To cite this article: S. Rousset et al., C. R. Physique 6 (2005).  2004 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Physical Review B, 2013

We report here in situ measurements of the evolution of the Ag(110) surface during Si growth, usi... more We report here in situ measurements of the evolution of the Ag(110) surface during Si growth, using scanning tunneling microscopy and grazing incidence x-ray diffraction. We provide compelling evidence of an Ag(110) surface reconstruction associated with the release of Ag atoms induced by the growth of Si nanoribbons. Our results are in agreement with a missing row reconstruction of the Ag layer underneath the nanoribbons. This challenges the current understanding of the Si growth on nonreconstructed Ag(110), interpreted within the framework of silicene models.