Photothermal Deflection Spectroscopy Investigations of Uranium Electrochemistry

1992 ◽  
Vol 294 ◽  
Author(s):  
James D. Rudnicki ◽  
Richard E. Russo
Keyword(s):  
Optical Absorption ◽  
Reaction Mechanisms ◽  
Uranium Oxide ◽  
Electrochemical Dissolution ◽  
Concentration Gradients ◽  
Photothermal Deflection Spectroscopy ◽  
First Results ◽  
Photothermal Deflection ◽  
Oxide Electrochemistry ◽  
Insight Into

ABSTRACTPhotothermal Deflection Spectroscopy (PDS) has been successfully applied to the study of uranium oxide electrochemistry. A brief description of PDS and preliminary results that demonstrate the technique are presented. Concentration gradients formed at the electrode surface are measured by this technique. The gradients give insight into the reaction mechanisms. There is some evidence of the initiation of non-electrochemical dissolution of the uranium oxide. Optical absorption by the uranium oxide is measured by PDS and the first results indicate that the absorption of the surface does not change during electrochemical experiments. This result is contrary to literature measurements of bulk samples that indicate that the optical absorption should be strongly changing.

Photothermal Deflection Spectroscopy Investigations of Uranium Electrochemistry - II

1993 ◽  
Vol 333 ◽  
Author(s):  
James D. Rudnicki ◽  
Richard E. Russo
Keyword(s):  
Optical Absorption ◽  
Saturated Calomel Electrode ◽  
Sample Surface ◽  
Oxidation Potential ◽  
Dissolution Mechanism ◽  
Concentration Gradients ◽  
Photothermal Deflection Spectroscopy ◽  
Photothermal Deflection ◽  
Oxide Electrochemistry

ABSTRACTPhotothermal Deflection Spectroscopy (PDS) has been applied to the study of uranium oxide electrochemistry. PDS measures the optical absorption of the sample surface and concentration gradients formed in the electrolyte. Both of these measurements are performed in situ under dynamic conditions. The combination of these two measurements provides information that can be used to infer the mechanism of the UO2 surface chemistry. These studies of the uranium dissolution mechanism are performed in pH 10.5 sodium sulfate electrolytes at 22°C. The electrolytes are free from oxygen, and complexing species. Our results suggest that dissolution of UO2 can occur at oxidizing potentials as low as -300 mV vs. saturated calomel electrode (SCE). The optical absorption and concentration gradient results provide evidence for a substantial surface change that occurs at an oxidation potential of +300 mV. The results show that the surface layer formed by this change dissolves slowly by a non-electrochemical reaction.

scholarly journals Subgap Absorption in Conjugated Polymers

1991 ◽  
Vol 228 ◽  
Author(s):  
M. Sinclair ◽  
C. H. Seager ◽  
D. McBranch ◽  
A. J. Heeger ◽  
G. L. Baker
Keyword(s):  
Optical Absorption ◽  
Conjugated Polymers ◽  
Absorption Edge ◽  
Spectral Region ◽  
Absorption Coefficients ◽  
Photothermal Deflection Spectroscopy ◽  
Integrated Optical ◽  
Integrated Optical Devices ◽  
Photothermal Deflection ◽  
Sample Age

ABSTRACTAlong with χ(3), the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of < 10-5, Photothermal Deflection Spectroscopy (PDS) is ideal for determining the absorption coefficients of thin films of “transparent” materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers poly[1,4-phenylenevinylene] (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm-1 to 10 cm-1. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration or fluorination.

Tritium Induced Defects in Amorphous Silicon

2004 ◽  
Vol 808 ◽  
Author(s):  
J. Whitaker ◽  
J. Viner ◽  
S. Zukotynski ◽  
E. Johnson ◽  
P.C. Taylor ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Defect Production ◽  
Photothermal Deflection Spectroscopy ◽  
Spin Resonance ◽  
Photothermal Deflection ◽  
Induced Defects ◽  
Hydrogenated Amorphous ◽  
Accumulation Of Defects ◽  
Insight Into

ABSTRACTWe report the growth of tritium induced defects in tritium doped hydrogenated amorphous silicon (a-Si:H,T) as measured by electron spin resonance (ESR) and photothermal deflection spectroscopy (PDS). The measurements allow one to examine the accumulation of defects in a-Si:H,T where the defect production mechanism is known. Defects produced by tritium decay are found to be much less numerous than the number of decayed tritium atoms and they are metastable like Staebler-Wronski defects. These results provide new insight into the metastable defect creation and the role of hydrogen motion.

Measurement of optical absorption in single quantum wells using photothermal deflection spectroscopy

1985 ◽  
Vol 47 (6) ◽  
pp. 591-593 ◽  
Author(s):  
A. F. S. Penna ◽  
Jagdeep Shah ◽  
A. E. DiGiovanni ◽  
A. Y. Cho ◽  
A. C. Gossard
Keyword(s):  
Optical Absorption ◽  
Quantum Wells ◽  
Single Quantum ◽  
Photothermal Deflection Spectroscopy ◽  
Photothermal Deflection

Optical Absorption in Polyacetylene: A Direct Measurement Using Photothermal Deflection Spectroscopy

1984 ◽  
Vol 53 (1) ◽  
pp. 86-89 ◽  
Author(s):  
B. R. Weinberger ◽  
C. B. Roxlo ◽  
S. Etemad ◽  
G. L. Baker ◽  
J. Orenstein
Keyword(s):  
Optical Absorption ◽  
Direct Measurement ◽  
Photothermal Deflection Spectroscopy ◽  
Photothermal Deflection
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