Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Electromagnetic shielding effectiveness of galvanostatically synthesized conducting polypyrrole films in the 300-2000 MHz frequency range
Date
1996-07-01
Author
Kaynak, A
Metadata
Show full item record
This work is licensed under a
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
.
Item Usage Stats
189
views
0
downloads
Cite This
Both far-field (plane wave) and near field shielding effectiveness (SE) measurements have been conducted on electrochemically synthesized conducting polypyrrole(PPy) films with wide ranging conductivity levels (10(-2) S/cm to 45 S/cm). Go-axial transmission line, TEM test cell and TE(10) waveguide techniques were employed to measure shielding effectiveness as a function of polymer conductivity, frequency and temperature. Highly doped polypyrrole films exhibited shielding levels, above 40 dB from 300 MHz to 2 GHz, which can make them attractive for consideration in shielding applications. However, a loss of 10 to 15 dB in the shielding effectiveness, for the samples aged for a period of two years at room temperature, was observed. SE of PPy films increased with the increase in the dopant concentration and decreased with frequency reaching a plateau at higher frequencies. However, corrected SE values as a function of frequency appeared relatively flat. The measurements made directly on the TEM-t cell would simulate high impedance condition (E-field) due to the capacitive coupling, and use of the correction factors therefore eliminated this condition, giving rise to corrected far-field SE values. Using the theory for plane wave shielding effectiveness of thin material shields, the agreement between the theory and experimental results were tested. Effect of temperature on the plane-wave SE of a lightly doped (0.006 M p-TS) PPy film was also investigated. Results showed significant increase in the SE with temperature. At room temperature the lightly doped PPy film with a dc conductivity of 0.01 S/cm was almost transparent to microwaves with very little reflection or absorption.
Subject Keywords
Organic compounds
,
Thin films
,
Electrical properties
,
Optical properties
URI
https://hdl.handle.net/11511/64350
Journal
MATERIALS RESEARCH BULLETIN
DOI
https://doi.org/10.1016/0025-5408(96)00038-4
Collections
Department of Engineering Sciences, Article
Suggestions
OpenMETU
Core
Optical properties of Cu3In5S9 single crystals by spectroscopic ellipsometry
Işık, Mehmet; Nasser, H.; Ahmedova, F.; Guseinov, A.; Hasanlı, Nızamı (2018-01-01)
Cu3In5S9 single crystals were investigated by structural methods of x-ray diffraction and energy dispersive spectroscopy and optical techniques of ellipsometry and reflection carried out at room temperature. The spectral dependencies of optical constants; dielectric function, refractive index and extinction coefficient, were plotted in the range of 1.2-6.2 eV from ellipsometric data. The spectra of optical constants obtained from ellipsometry analyses and reflectance spectra presented a sharp change around ...
Intrinsic photoconductivity of P3HT films measured by time-resolved THz spectroscopy
Esentürk, Okan; Heilweil, Edwin J. (2007-12-01)
Intrinsic photoconductivities of P3HT polymers were measured and compared by using optical pump-THz probe spectroscopy. The charge carrier mobility shows a clear dependence on the molecular weight and dispersion index of the polymers.
Structural and optical properties of thermally evaporated Ga-In-Se thin films
IŞIK, MEHMET; Güllü, Hasan Hüseyin (2014-05-30)
In this paper, structural and optical properties of Ga-In-Se (GIS) thin films deposited by thermal evaporation technique have been investigated. The effect of annealing was also studied for samples annealed at temperatures between 300 degrees C and 500 degrees C. X-ray diffraction, energy dispersive X-ray analysis and scanning electron microscopy have been used for structural characterization. It was reported that increase of annealing temperature results with better crystallization and chemical composition...
Optical band gap and dispersion of optical constants of Cu-Ga-S thin films
Isik, M.; Gullu, H. H.; COŞKUN, EMRE; Hasanlı, Nızamı (2019-01-01)
Thermally deposited Cu-Ga-S thin films were optically characterized by means of experimental techniques of transmission measurements. The analyses of transmittance spectra were accomplished by derivative spectrophotometry analyses to get gap energies of thin films. The transmittance spectra of thin films annealed at different temperatures presented interference fringes which were analyzed by Swanepoel envelope method. The wavelength dependencies of optical parameters; refractive index (n), real part of comp...
Near infrared interference filter design and the production with ion-assisted deposition techniques
Aydoğdu, Selçuk; Esendemir, Akif; Department of Physics (2012)
Near infrared region (NIR) of the electromagnetic spectrum (EM) is defined as 700nm to 1400nm wavelength interval by International Commission on Illumination(CIE). This wavelength interval is extensively used for target acquisition, night vision, wireless communication etc. Therefore, filtering the desired portion of EM spectra becomes a need for that kind of applications. Interference filters are multilayer optical devices which can be designed and produced for the desired wavelength intervals. The product...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
A. Kaynak, “Electromagnetic shielding effectiveness of galvanostatically synthesized conducting polypyrrole films in the 300-2000 MHz frequency range,”
MATERIALS RESEARCH BULLETIN
, pp. 845–860, 1996, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/64350.