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In this report, local electronic structures of steps and terraces on rutile TiO2 single crystal faces were studied by second harmonic and sum frequency generation (SHG/SFG) spectroscopy. We attained selective measurement of the local electronic states of the step bunches formed on the vicinal (17 18 1) and (15 13 0) surfaces using a recently developed step-selective probing technique. The electronic structures of the flat (110)-(1×1) (the terrace face of the vicinal surfaces) and (011)-(2×1) surfaces were also discussed. The SHG/SFG spectra showed that step structures are mainly responsible for the formation of trap states, since significant resonances from the trap states were observed only from the vicinal surfaces. We detected deep hole trap (DHT) states and shallow electron trap (SET) states selectively from the step bunches on the vicinal surfaces. Detailed analysis of the SHG/SFG spectra showed that the DHT and SET states are more likely to be induced at the top edges of the step bunches than on their hillsides. Unlike the SET states, the DHT states were observed only at the step bunches parallel to [formula] [equivalent to the step bunches formed on the (17 18 1) surface]. Photocatalytic activity for each TiO2 sample was also measured through methylene blue photodegradation reactions and was found to follow the sequence: (110) < (17 18 1) < (15 13 0) < (011), indicating that steps along [0 0 1] are more reactive than steps along [formula]. This result implies that the presence of the DHT states observed from the step bunches parallel to [formula] did not effectively contribute to the methylene blue photodegradation reactions. [ABSTRACT FROM AUTHOR]

Investigates the crystal orientations and the residual stresses of diamond films produced by acetylene-oxygen combustion-flame method. Components of the total residual stresses of diamond film on a substrate; Presence of anisotropic stresses in the crystals; Results of the investigation.

Molecular orbital calculations have shown that the structures of both trans and cis isomers of N,N’-disubstituted indigo dyes are considerably twisted about the central C=C bond. The twisting angle of the cis isomer is not always larger than that of the corresponding trans isomer, indicating that the large hypsochromic shift on the trans→cis isomerization of N,N’-disubstituted indigo dyes cannot be explained by the twisted structure of the cis isomer. It is shown that the hypsochromic shift can be ascribed to a larger contribution of the zwitterionic form to the resonance hybrid structure in the lowest excited singlet state S1 than in the ground state S0 .This makes the repulsion between the negative charges on the carbonyl oxygen atoms enhanced and the instability of the cis configuration compared to the trans configuration much larger in the S1 state than in the S0 state and leads to a larger vertical S1 ←S0 transition energy for the cis isomer than for the trans isomer. [ABSTRACT FROM AUTHOR]

Studies the molecular orbital and resonance Raman spectra of the triplet state of N,N,N',N'-tetramethyl-p-phenylenediamine. Geometry of each state; Optimized structures of the ground state and the radical cation.

Single-crystal CVD diamond specimens were implanted with 1-MeV He+ ions at fluences ranging from 1014 to 1016 cm-2 and analyzed using coherent acoustic phonon spectroscopy. The coherent acoustic phonon response varies greatly with implantation fluence and provides depth-dependent information about the implantation defect-induced modification of diamond's optical characteristics. The results indicate an increase in the real and imaginary refractive index, as well as a sign reversal of the photoelastic coefficients at higher levels of implantation damage. These studies provide insight into the application of ion implantation to the fabrication of diamond-based photonic devices. [ABSTRACT FROM AUTHOR]

A correction to the article "Ion implantation induced modification of optical properties in singlr-crystal diamond studied by coherent acoustic phonon spectroscopy" that was published in the 2012 issue is presented.