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Your search keyword '"Kamada, M."' showing total 35 results
Start Over Author "Kamada, M." Journal journal of electron spectroscopy and related phenomena
35 results on '"Kamada, M."'

7. VUV optical spectra of hydrogen-bonded ferroelectrics PbHPO4 and PbHAsO4

Author

Nobuhito Ohno, Deguchi K, Kamada M, and Kida N

Subjects
Radiation, Absorption spectroscopy, Extended X-ray absorption fine structure, Chemistry, Exciton, Analytical chemistry, Photon energy, Condensed Matter Physics, Ferroelectricity, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Reflection (mathematics), Absorption edge, Attenuation coefficient, Physical and Theoretical Chemistry, Atomic physics, Spectroscopy
Abstract

Reflection and absorption spectra of hydrogen-bonded ferroelectric PbHPO 4 and PbHAsO 4 have been investigated for the first time in the energy range from 3 to 25 eV. The first exciton transitions observed around 5.2–5.7 eV are assigned as Pb 2+ 6s→6p interband transition. A logarithmic plot of the absorption coefficient at the fundamental absorption edge vs. photon energy gives a straight line above 30 K. It is found that the temperature dependence of steepness parameter σ is scaled with the spontaneous polarization P S . These results are discussed in terms of the exciton–lattice interaction based on the Urbach rule.

Published
1999

8. Study of ion desorption induced by the core-level excitation on the CaF2(111) surface

Author

Shin-ichiro Tanaka, M Mase, M Nagasono, and Kamada M

Subjects
Radiation, Chemical substance, Chemistry, Analytical chemistry, Synchrotron radiation, Photon energy, Condensed Matter Physics, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, law.invention, Ion, Condensed Matter::Materials Science, Magazine, law, Desorption, Physical and Theoretical Chemistry, Atomic physics, Science, technology and society, Spectroscopy, Excitation
Abstract

Desorption of F+ induced by core-level excitation with synchrotron radiation has been investigated on the CaF2(111) film produced on Si(111). The ion yield is proportional to electron yield in the region of the Ca-2p edge, while an enhancement of the ion yield is observed at the photon energy for the F-1s core-exciton. The peak corresponding to the F-1s excitation observed in the ion yield is shifted from that in the electron yield by about −1.2 eV, which is predominantly ascribed to the change in the Madelung potential at the surface. The electron–ion coincidence study shows that the F+ desorption is directly stimulated via a decay of the F-1s surface core-exciton, while secondary-electron stimulated desorption is the predominant process after the creation of Ca-2p hole.

Published
1998

33. Radiative transitions in C 60 thin films under SR excitation

Author

Terekhin, M.A., Svechnikov, N.Yu., Stankevitch, V.G., Kolmakov, A.A., Stepanov, V.A., Bezmelnitsin, N., Kamada, M., Kan'no, K., and Akimoto, I.

Abstract

Photoluminescent (PL) properties of pure C 60 thin solid films were investigated in the emission range of 1.2-2.4eV over a wide temperature range, under excitation with 36eV photon from the undulator beamline of UVSOR. Degradation of PL intensity of the 1.67eV band was discovered under long-time irradiation in ultra-high vacuum condition and its dose dependence was examined at various ambient conditions. Temperature dependence of PL intensity from 10 K to 300 K exhibited an anomaly at the vicinity of the structural phase transition T c ∼ 250K. Time-resolved decay measurements exhibited the decay components of 1.2±0.1ns and of about 400μs. From the influence of oxygen on degradation of PL intensity, we suppose that the triplet state is highly populated and non-radiative decay process mainly occur.

Published
1996
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