Surface of silicates

Un article de Surface du verre et interfaces.

Elin Sondergard - Anne Lelarge

Silicate are widespread materials found in nature and also in many technologies. The surface arrangement is a key parameter in understanding the nucleation of thin films or the reactivity of these materials. However, little is know about the actually atomic structure of the surface of silicates. This is mainly due to difficulties in the preparation and invesitgation of insulating systems. Obviously the surface of the amorphous silicates presents a major challenge as it is exclude the use of diffraction based techniques. Due to this we have over some years been attempting to use HAStechniques to investigate the spatial and dynamic properties of Silicates

2 aspects are under investigation:

• Amorphous silica: no current technique can easily be used to map atomic possitions on amorphous surfaces. Therefore we have investigated both the origine of the roughness distribution of silica using AFM as well as the vibrational properties.

• Crystalline Quartz surfaces, we are currently working on the understading of the step structure and surface reconstructions on Silica.

 

Collaborations

• Prof. Bodil Holst Department of Physics and Technology- University of Bergen, Norway

• Dr. Damien Vandembroucq Laboratoire Physique et Mécanique des Milieux Hétérogènes - UMR 7636 - ESPCI, Paris, France

 

Some publications

• “Frozen capillary waves on glass surfaces: An AFM study”,

T. Sarlat, A. Lelarge, E. Søndergård and D. Vandembroucq, European Physical Journal B, Vol 54, n°1, pp. 121-126 (2006).

• “Observation of the boson peak at the surface of vitreous silica”,

W. Steurer, A. Apfolter, M. Koch, W.E. Ernst, B. Holst, E. Sondergard and R.J. Manson, Physical Review Letter, Vol. 99, n°3, pp. 035503-1- 4 (2007).

• “Low-energy surface phonons on alpha-quartz (0001)”,

W. Steurer, A. Apfolter, M. Koch, W.E. Ernst, B. Holst, E. Sondergard and S.C. Parker, Physical Review B, Vol. 78, pp. 3 (2008).

• “Surface dynamics measurements of silica glass”,

W. Steurer, A. Apfolter, M. Koch, W.E. Ernst, E. Sondergard, J.R. Manson and B. Holst, Physical Review B, Vol. 78, pp.4 (2008).

• “Vibrational excitations of glass observed using helium atom scattering”,

W. Steurer, A. Apfolter, M. Koch, W.E. Ernst, E. Sondergard, J.R. Manson and B. Holst, Journal of Physics Condensed Matter, Vol. 20, pp.22 (2008).

• “Anomalous phonon behavior: Blueshift of the surface boson peak in silica glass with increasing

temperature”, W. Steurer, A. Apfolter, M. Koch, M., W.E. Ernst, E. Sondergard, J.R. Manson and B. Holst, Physical Review Letters, Vol. 100, pp. 13 (2008).