Identification of crazing in sol-gel thin layers

Identification of crazing in sol-gel thin layers

Hervé Piombini  Christophe Boscher  Anne-Laure Barre  Jérémy Avice 

CEA, DAM Le Ripault, 37260 Monts, France

Corresponding Author Email:
31 December 2017
| Citation

Most of the optical components of MegaJoule laser working in transmission are coated with an antireflective sol-gel layer. The colloidal silica is used for lenses made of silica since its refractive index is close to 1.22 so that we can build antireflective layers at 1 ω (1 053 nm) if their thickness is 216 nm and antireflective layer at 3 ω  (351 nm) 72 nm.

These coatings are deposited by dip coating and are quite fragile mechanically. The coated components are then immersed into vapor of ammonia to harden them and to increase their mechanical resistance against wiping, cleaning, handling or procedures for maintenance. This processing causes a layer shrinkage in thickness which is sometimes accompanied by crazing for thicker layers and longer exposition times. We want to study this crazing effect in order to reduce it by optimizing the parameters of deposition and treatment. As a fast way to evaluate the crazing process we used video optical microscopy and a scanning stage at the sample position


microscopy, image analysis, diffusion measurement, sol-gel, thin films

1. Introduction
2. Étude de la caméra utilisée et éclairage
3. Augmentation de la dynamique de la caméra
4. Focalisation automatique
5. Caractérisation du faïençage par traitement d’image
6. Préparation des échantillons caractérisés
7. Résultats
8. Conclusion

André M. L. (1999) .The French MegaJoule Project (LMJ). Fusion Eng. and Des., 44, p. 43-49. Avice J., Boscher C., Vaudel G., Brotons G., Juvé V., Edely M., Méthivier C., Gusev V.E.,

Belleville P., Piombini H., Ruello P. (2017). Controlling the Nanocontact Nature and the Mechanical Properties of a Silica Nanoparticle Assembly. J. Phys. Chim. C

Ayouch A, Dieudonné X, Vaudel G.,Piombini H.,Vallé K.,Gusev V,Belleville P and,Ruello P. (2012). Elasticity of an Assembly of Disordered Nanoparticles Interacting via Either van der Waals-Bonded or Covalent-Bonded Coating Layers. ACS NANO 6, p. 10614-10621.

Belleville  P.  and  Floch  H.  (1994).  Ammonia  hardening  of  porous  silica  antireflective coatings. Proc. SPIE 2288, p. 25-32.

Belleville P., Floch H., Pegon M. (1994). Sol-Gel Broadband Antireflective Coatings for Advanced Laser-Glass Amplifiers. Proc. SPIE 2288, p. 14-24.

Belleville P., Prené P., Bonnin C., Beaurain L., Montouillout Y. (2004). How smooth chemistry allows high-power laser optical coating preparation. Proc. SPIE 5250, p. 196-202.

Boscher C., Avice J., Belleville P., Piombini H., Vallé K. (2017). Etude du durcissement ammoniac de couche mince sol-gel. Actes du colloque CMOI 2017, Instrument, Mesure, Métrologie, Le Mans.

Brenner J.F., Dew B.S., Horton J.B., King T., Neurath P.W., SellersW.D. (1976). An automated microscope for cytologic research a preliminary evaluation, J. Histochem Cytochem.

Clarke  A.R.,  Eberhardt  C.N.  (2002).  Microscopy  Techniques  for  Materials  Science, Woodhead Publishing.

Compoint F., Fall D., Piombini H., Belleville P., Montouillou Y., Duquennoy M., Ouaftouch M., Jenot F., Piwakowski B., Sanchez C. (2016). Sol-gel proceesed hybrid silica -PDMS layers for the optics of high-power laser flux systems. Journal of Materials Science, vol. 51, n° 11 p. 50-5031.

Dolleiser  M.,  Hashemi-Nezhad  S.R.  (2002).  A  fully  automated  optical  microscope  for analysis of particle tracks in solids. Nucl. Instrum. Meth. B, 198, p. 98-107.

Firestone L., Cook K., Culp K., Talsania N., Preston K., Jr, (1991) Comparison of Autofocus Methods for Automated Microscopy, Cytometry, 12, p. 195-206.

Harms H. et Aus H.M. (1984). Comparison of Digital Focus Criteria for a TV Microscope System, Cytometry, 5, p. 236-243. V500_TechManual.pdf. Methods_and_Concepts_in_the_Life_Sciences/Microscopy.

IEEE Standard for a High-Performance Serial Bus, IEEE Std. 1394-2008.2008-10-21, doi:10.1109/IEEESTD.2008.4659233.

Landau  L.D,  Levich  V.G.  (1942).  Dragging  of  a  liquid  film  by  moving  plate.  Acta Physicochim. URSS vol. 17, 41.

Liu X., Huang Y., Kang J. U. (2011). Dark-field illuminated reflectance fiber bundle endoscopic microscope. J Biomed Opt, vol. 16, n° 4, 046003

Mouchart J. J. , Lagier G., and Pointu B. (1985) Détermination des constantes optiques n et k de matériaux faiblement absorbants. Applied Optics, vol. 24, n° 12.

Piombini H., Voarino P. (2007). Apparatus designed for very accurate measurement of the optical reflection. Applied Optics, vol. 46, n° 36, p. 8609-8618.

Piombini H., Soler D., Voarino P. (2008). New device to measure the reflectivity on steeply curved surface. Proc. SPIE 7018, 70181B 2008.

Piombini  H.,  Caillon  L.  (2009).  Reflectance  measurement  of  spherical  samples.  Optical review vol. 16, n° 6.

Piombini H., Sabary F., Marteau D. , Voarino P., Cheveau G., Kroll H., Valette N. and Grèzes-Besset C. (2014). Evaluation of enhanced mirror for LMJ reflector industrial production. Appl. Opt. vol. 53, n° 4, p. A305-A313.

Puetz J., Aegerter M.A (2004). Dip coating technique, Sol-gel Technologies for glasses producers and users. Springer US, New York, p. 37-48.

Sazaki G., Nagashima K., Murata K., Furukawa Y. (2016). In-situ observation of crystal surfaces by optical microscopy Prog. Cryst. Growth Ch. Vol. 62, n° 2, p. 408-412.

Stöber W. et al (1968). Controlled growth of monodisperse silica spheres in the micron size range. Journal of Colloid and Interface Science, vol. 26, n° 1, p. 62-69.

Voarino P., Piombini H., Sabary F., Marteau D., Dubard J., Hameury J., and Filtz J. R. (2008). High-accuracy measurements of the normal specular reflectance. Applied optics vol. 47, n° 13, p. C303-C309