Structural Dependence of the Elastic Constants of Polymeric Langmuir-Blodgett Films Studied Using Brillouin Scattering

1990 ◽  
Vol 188 ◽  
Author(s):  
Sukmock Lee ◽  
J. R. Dutcher ◽  
B. Hillebrands ◽  
G. I. Stegeman ◽  
W. Knoll ◽  
...  
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Elastic Constants ◽  
Brillouin Scattering ◽  
Langmuir Blodgett ◽  
Structural Dependence ◽  
Langmuir Blodgett Films

ABSTRACTWe have used Brillouin scattering to study the dependence of the elastic constants of uniaxial polymeric Langmuir-Blodgett thin films on the thickness of the polymeric molecule monolayers. With increasing monolayer thickness, an overall decrease in the elastic constants and an increase in the refractive index n33 was observed.

A new method for measuring refractive index and thickness of Langmuir-Blodgett films of ttb-PcSiCl2

1989 ◽  
Vol 178 (1-2) ◽  
pp. 525-528 ◽  
Author(s):  
Li Yajun ◽  
Wang Xianxiu ◽  
Pang Xiaomin ◽  
Hua Yuling ◽  
Fan Junqing
Keyword(s):  
Refractive Index ◽  
New Method ◽  
Langmuir Blodgett ◽  
Langmuir Blodgett Films

Structural and electronic properties of pentacene/pentacenequinone thin films prepared by Langmuir–Blodgett technique

2009 ◽  
Vol 74 (4) ◽  
pp. 565-579
Author(s):  
Martin Weis ◽  
Katarína Gmucová ◽  
Daniel Haško ◽  
Jarmila Müllerová
Keyword(s):  
Thin Films ◽  
Electronic Properties ◽  
Electrochemical Techniques ◽  
Energy Band Diagram ◽  
Amorphous Structure ◽  
Metallic Surface ◽  
Amorphous Thin Films ◽  
Langmuir Blodgett ◽  
Structural And Electronic Properties ◽  
Langmuir Blodgett Films

Structural and electronic properties of pentacene/pentacenequinone thin films prepared on various solid-state substrates by the Langmuir–Blodgett technique are reported. Amorphous structure of the prepared films has been proved by XRD measurements. Oxygen-related defects have been identified in the Langmuir–Blodgett films as a consequence of the exposure of pentacene Langmuir layer to air. Crystallization induced by thermal treatment of the prepared amorphous thin films has been observed. Electronic properties of pentacene/ pentacenequinone Langmuir–Blodgett films have been investigated in the contact-less architecture using electrochemical techniques. The energy band diagram of the amorphous pentacene/pentacenequinone Langmuir–Blodgett film on a metallic surface was constructed from the obtained electrochemical data.

scholarly journals Elastic Constants of Diamond-Like Carbon Films by Surface Brillouin Scattering

1999 ◽  
Vol 593 ◽  
Author(s):  
A.C. Ferrari ◽  
J. Robertson ◽  
R. Pastorelli ◽  
M.G. Beghi ◽  
C.E. Bottani
Keyword(s):  
Thin Films ◽  
Amorphous Carbon ◽  
Elastic Constants ◽  
Acoustic Waves ◽  
Brillouin Scattering ◽  
Surface Acoustic Waves ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Amorphous Carbon Films ◽  
Tetrahedral Amorphous Carbon

ABSTRACTThe elastic constants of thin Diamond-Like Carbon (DLC) films supply important information, but their measurement is difficult. Standard nanoindentation does not directly measure the elastic constants and has strong limitations particularly in the case of hard thin films on softer substrates, such as tetrahedral amorphous carbon on Si. Surface acoustic waves provide a better mean to investigate elastic properties. Surface Brillouin scattering (SBS) intrinsically probes acoustic waves of the wavelength which is appropriate to test the properties of films in the tens to hundreds of nanometers thickness range. SBS can be used to derive all the isotropic elastic constants of hard-on-soft and soft-on-hard amorphous carbon films of different kinds, with thickness down to less than 10 nm. The results help to resolve the previous uncertainties in mechanical data. The Young's modulus of tetrahedral amorphous carbon (ta-C) turns out to be lower than that of diamond, while the moduli of hydrogenated ta-C (ta-C:H) are considerably lower than those of ta-C because of the weakening effect of C-H bonding.

Elastic Properties of Diamond Like Carbon Thin Films: a Brillouin Scattering Study

1996 ◽  
Vol 444 ◽  
Author(s):  
O. R. Monteiro ◽  
I. G. Brown ◽  
R. Sooryakumar ◽  
M. Chirita
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Elastic Constants ◽  
Brillouin Scattering ◽  
Deposition Process ◽  
Hard Coatings ◽  
Vacuum Arc ◽  
Deposition Parameters ◽  
Scattering Study ◽  
Isotropic Solids

AbstractDiamondlike carbon (DLC) thin films have been widely used as hard coatings in a variety of applications where increased wear resistance and hardness are required. Vacuum arc DLC films are among the hardest, with measured hardness values of up to 68 GPa. In our deposition process a repetitively pulsed bias voltage is applied to the substrate, which controls the energy of the incoming C ions. DLC chemical and mechanical properties are strongly affected by the energy of the depositing ions. In this paper, we relate the mechanical properties of these films to the deposition parameters, and describe our initial Brillouin scattering measurements of the elastic constants of monolithic DLC films. Evidence for bulk longitudinal and surface Rayleigh excitation in films with thickness of 50 and 500 nm has been observed. Since the DLC films are amorphous, they are modeled as isotropic solids and the elastic constants CII and C44 are derived.

scholarly journals Elastic Constants of Diamond Like Carbon Films by Surface Brillouin Scattering

1999 ◽  
Vol 594 ◽  
Author(s):  
A. C. Ferrari ◽  
J. Robertson ◽  
R. Pastorelli ◽  
M. G. Beghi ◽  
C. E. Bottani
Keyword(s):  
Thin Films ◽  
Amorphous Carbon ◽  
Elastic Constants ◽  
Acoustic Waves ◽  
Brillouin Scattering ◽  
Surface Acoustic Waves ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Amorphous Carbon Films ◽  
Tetrahedral Amorphous Carbon

AbstractThe elastic constants of thin Diamond-Like Carbon (DLC) films supply important information, but their measurement is difficult. Standard nanoindentation does not directly measure the elastic constants and has strong limitations particularly in the case of hard thin films on softer substrates, such as tetrahedral amorphous carbon on Si. Surface acoustic waves provide a better mean to investigate elastic properties. Surface Brillouin scattering (SBS) intrinsically probes acoustic waves of the wavelength which is appropriate to test the properties of films in the tens to hundreds of nanometers thickness range. SBS can be used to derive all the isotropic elastic constants of hard-on-soft and soft-on-hard amorphous carbon films of different kinds, with thickness down to less than 10 nm. The results help to resolve the previous uncertainties in mechanical data. The Young's modulus of tetrahedral amorphous carbon (ta-C) turns out to be lower than that of diamond, while the moduli of hydrogenated ta-C (ta-C:H) are considerably lower than those of ta-C because of the weakening effect of C-H bonding.

Highly ordered thin films of polyheterocycles: A synchrotron radiation study of polypyrrole and polythiophene Langmuir-Blodgett films

1989 ◽  
Vol 28 (1-2) ◽  
pp. 229-236 ◽  
Author(s):  
T.A. Skotheim ◽  
X.Q. Yang ◽  
J. Chen ◽  
P.D. Hale ◽  
T. Inagaki ◽  
...  
Keyword(s):  
Thin Films ◽  
Synchrotron Radiation ◽  
Langmuir Blodgett ◽  
Radiation Study ◽  
Langmuir Blodgett Films

scholarly journals Langmuir–Blodgett Films of Polyvinylamine Modified by Perfluoroacylation. Preparation of Super Thin Films

1988 ◽  
Vol 17 (7) ◽  
pp. 1223-1224 ◽  
Author(s):  
Akira Sekiya ◽  
Masanori Tamura ◽  
Hiroyasu Ishida ◽  
Masako Watanabe
Keyword(s):  
Thin Films ◽  
Langmuir Blodgett ◽  
Langmuir Blodgett Films
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