- Access by Xinjiang University
Growth of a collapsing Langmuir monolayer
Phys. Rev. E 73, 051608 – Published 24 May, 2006
DOI: https://doi.org/10.1103/PhysRevE.73.051608
Abstract
Langmuir monolayers of stearic acid on Co ions in the aqueous subphase have been deposited at different stages of constant pressure collapse, on hydrophilic Si(001) using a modified version of the inverse Langmuir-Schaefer method of horizontal deposition. The electron density profiles (EDPs) along the depth of the deposited films, extracted from the x-ray reflectivity data, show that a monolayer to bi-molecular layer transformation takes place after collapse. The molecules in the lower monolayer have asymmetric configurations with head groups touching water and tails in air, whereas molecules in the upper layer are in symmetric configurations with tails on both sides of the heads. Atomic force microscopy images of the deposited films after collapse, however, show nearly circular islands of height more than that of the bimolecular layer observed in the EDP. As pressure increases, ridges are seen to coexist with these islands. Although the coverage of such islands and ridges is low, they play an important role in determining the growth mode. The growth of the wetting and island layers, taken together, has a striking similarity with the Stranski-Krastanow mode, observed usually for heteroepitaxial growth.
Article Text
References (21)
- A. E. H. Love, A Treatise on the Mathematical Theory of Elasticity (Dover Publications, New York, 1927).
- I. Kovács and L. Zsoldos, Dislocations and Plastic Deformation (Pergamon Press, Oxford, 1973).
- M. C. Petty, Langmuir-Blodgett Films: An Introduction (Cambridge University Press, Cambridge, U.K., 1996).
- G. L. Gaines, Insoluble Monolayers at Liquid-Gas Interfaces (Interscience, New York, 1966).
- J. P. Kampf, C. W. Frank, E. E. Malmstörm, and C. J. Hawker, Science 283, 1730 (1999).
- S. Kundu, A. Datta, and S. Hazra, Langmuir 21, 5894 (2005).
- C. Gourier, C. M. Knobler, J. Daillant, and D. Chatenay, Langmuir 18, 9434 (2002).
- M. K. Mukhopadhyay, M. K. Sanyal, A. Datta, J. Webster, and J. Penfold, Chem. Phys. Lett. 407, 276 (2005).
- A. Datta, S. Kundu, M. K. Sanyal, J. Daillant, D. Luzet, C. Blot, and B. Struth, Phys. Rev. E 71, 041604 (2005).
- I. Daruka and A.-L. Barabási, Phys. Rev. Lett. 79, 3708 (1997).
- V. A. Shchukin and D. Bimberg, Rev. Mod. Phys. 71, 1125 (1999).
- W. Theis and R. M. Tromp, Phys. Rev. Lett. 76, 2770 (1996).
- K. J. Caspersen, A. R. Layson, C. R. Stoldt, V. Fournee, P. A. Thiel, and J. W. Evans, Phys. Rev. B 65, 193407 (2002).
- A. Pundt, M. Getzlaff, M. Bode, R. Kirchheim, and R. Wiesendanger, Phys. Rev. B 61, 9964 (2000).
- P. Hähner, K. Bay, and M. Zaiser, Phys. Rev. Lett. 81, 2470 (1998).
- M. Zaiser, F. M. Grassett, V. Koutsos, and E. C. Aifantis, Phys. Rev. Lett. 93, 195507 (2004).
- J. K. Basu, S. Hazra, and M. K. Sanyal, Phys. Rev. Lett. 82, 4675 (1999).
- L. G. Parratt, Phys. Rev. 95, 359 (1954); J. K. Basu and M. K. Sanyal, Phys. Rep. 363, 1 (2002).
- J. Daillant and A. Gibaud, X-Ray and Neutron Reflectivity: Principles and Applications (Springer, Berlin, 1999); M. Tolan, X-Ray Scattering from Soft Matter Thin Films (Springer, Berlin, 1999).
- S. Kundu, S. Hazra, S. Banerjee, M. K. Sanyal, S. K. Mandal, S. Chaudhuri, and A. K. Pal, J. Phys. D 31, L73 (1998),.
- V. M. Kaganer, H. Möhwald, and P. Dutta, Rev. Mod. Phys. 71, 779 (1999).