Changes in refractive index and in chemical state of synchrotron radiation irradiated fluorinated polyimide films

1996 ◽  
Vol 14 (4) ◽  
pp. 2470-2474 ◽  
Author(s):  
Yasuko Yamada Maruo ◽  
Shigekuni Sasaki ◽  
Tsuneyuki Haga ◽  
Hiroo Kinoshita ◽  
Toshiyuki Horiuchi ◽  
...  
Keyword(s):  
Refractive Index ◽  
Synchrotron Radiation ◽  
Chemical State ◽  
Polyimide Films ◽  
Fluorinated Polyimide

scholarly journals Optical constants of sputtered beryllium thin films determined from photoabsorption measurements in the spectral range 20.4–250 eV

2020 ◽  
Vol 27 (1) ◽  
pp. 75-82
Author(s):  
Mikhail Svechnikov ◽  
Nikolay Chkhalo ◽  
Alexey Lopatin ◽  
Roman Pleshkov ◽  
Vladimir Polkovnikov ◽  
...  
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Synchrotron Radiation ◽  
Initial Data ◽  
Absorption Coefficient ◽  
Energy Range ◽  
Transmission Coefficient ◽  
Radiation Source ◽  
Optical Constants ◽  
Free Standing

In this work, the refractive index of beryllium in the photon energy range 20.4–250 eV was experimentally determined. The initial data include measurements of the transmittance of two free-standing Be films with thicknesses of 70 nm and 152 nm, as well as reflectometric measurements of similar films on a substrate. Measurements were carried out at the optics beamline of the BESSY II synchrotron radiation source. The absorption coefficient β was found directly from the transmission coefficient of the films, and the real part of the polarizability δ was calculated from the Kramers–Kronig relations. A comparison is carried out with results obtained 20 years ago at the ALS synchrotron using a similar methodology.

Control of Refractive Index of Fluorinated Polyimide by Proton Beam Irradiation

2013 ◽  
Vol 52 (1R) ◽  
pp. 012601 ◽  
Author(s):  
Yukitaka Arai ◽  
Yoshimichi Ohki ◽  
Keisuke Saito ◽  
Hiroyuki Nishikawa
Keyword(s):  
Refractive Index ◽  
Proton Beam ◽  
Beam Irradiation ◽  
Proton Beam Irradiation ◽  
Fluorinated Polyimide

Densification of Sio Gel Films by Synchrotron Radiation and its Dependence on Photon Energy

1994 ◽  
Vol 375 ◽  
Author(s):  
Hiroaki Imai ◽  
Koichi Awazu ◽  
Masaru Yasumori ◽  
Hiroshi Hirashima ◽  
Hideo Onuki
Keyword(s):  
Refractive Index ◽  
Infrared Spectroscopy ◽  
Synchrotron Radiation ◽  
Energy Dependence ◽  
Photon Energy ◽  
Oh Groups

AbstractThe interaction of synchrotron radiation (SR) emitted from a polarizing undulator with SiO2 gel films was investigated by ellipsometry and infrared spectroscopy. The photon energy in SR was varied in the range of 6.4−17.8 eV using an Onuki-type undulator in order to study the energy dependence of the interaction. We found that an increase of refractive index, a decrease of thickness of the films and a loss of OH groups were induced by photons with energies above ˜9 eV although any changes were not observed with photons below ˜7 eV. These results suggest that SiO2 gel films are densified through electronic processes stimulated by the energetic photons.

Stiff Polyimides: Chain Orientation And Anisotropy Of The Optical And Dielectric Properties Of Thin Films

1991 ◽  
Vol 227 ◽  
Author(s):  
D. Boese ◽  
S. Herminghaus ◽  
D. Y. Yoon ◽  
J. D. Swalen ◽  
J. F. Rabolt
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Refractive Index ◽  
Dielectric Properties ◽  
Dielectric Constants ◽  
Polyimide Films ◽  
Lorenz Equation ◽  
Out Of Plane ◽  
Large Anisotropy ◽  
Uv Visible

ABSTRACTThin films of poly(p-phenylene biphenyltetracarboximide), prepared by thermal imidization of the precursor poly(amic acid) on substrates, have been investigated by optical waveguide, UV-visible, infrared (IR), and dielectric spectroscopies. The polyimide films exhibit an extraordinarily large anisotropy in the refractive indices with the in-plane index n║ = 1.852 and the out-of-plane index n┴ = 1.612 at 632.8 nm wavelength, indicating a strong preference of polymer chains to orient along the film plane. No discernible effect of the film thickness on this optical anisotropy is found in the range of ca. 0.4 μm to 7.8 μm in thickness. The frequency dispersion of the in-plane refractive index to 1.06 μm wavelength is consistent with the results calculated by the Lorentz-Lorenz equation from the UV-visible spectrum. The contribution from the entire IR range from 7000 to 200 cm,−1 computed by the Spitzer-Kleinmann dispersion relations from the measured spectra, adds ca. 0.07 to the in-plane refractive index n║. Approximately the same increase is assumed for the out-of-plane index n┴, based on the tilt-angle dependent IR results. Application of the Maxwell relation leads to the out-of-plane dielectric constant ε┴≃2.8 at ca. 1013 Hz, as compared with the measured value of ca. 3.0 at 106 Hz. Assuming this small difference to remain the same for the in-plane dielectric constants ε║, we obtain a a very large anisotropy in the dielectric properties of these polyimide films with the estimated in-plane dielectric constant ε║≃3.5 at ca. 1013 Hz, and ε.≃3.7 at 106 Hz.

Sign in / Sign up

Export Citation Format

Share Document