Photorefractive Effect and Observation of the Matrix Relaxation around Photo-Excited Centres in Condensed Matter

Abstract

PACS. 71.38 -Polarons and electron-phonon interactions. PACS. 78.20 -Optical 'properties and materials.

Time-resolved photothermal and photoacoustic methods applied to photoinduced processes in solution

“…The volume change per excited ion was found to amount to a contraction of 7 X 10"30 m3 which corresponds, as calculated by the authors on the basis of symmetry considerations of the ground and excited states involved, to a contraction by 0.14 X 10~10 m (0.14 A) of the Mn-0 equilibrium distance after excitation. 90 In contrast to other aqueous ion complexes, e.g., Cu(H20)62+ and Co(H20)62+ which show no volume changes and are used as references for the photocalorimetric measurements, Mn(H20)62+ undergoes intersystem crossing and the slow decay of the transient (4.6 ms) makes possible the detection of a volume change in this case.…”

“…This small value contrasts with the 10 times larger change calculated by Strauss and Walder for the variation of the Mn-0 bond length (anisotropic) upon excitation of the hexaaquo Mn complex (vide supra) . 90 An even smaller radial decrease was calculated by the same method for the 4A2 -* 2E transition of Cr(bpy)3+ and an alternative explanation was offered for the origin of the volume change, viz. to a photoaquation of the complex in the excited state.…”

Photoinduced volume changes associated with the early transformations of bacteriorhodopsin: a laser-induced optoacoustic spectroscopy study

“…In addition to Al/th, a volume change AV, originating from a molecular process other than heating (i.e., conformational or solvation changes) may induce a pressure change and, consequently, an optoacoustic signal (Callis et al, 1972;Westrick et al, 1987;Ort and Parson, 1979;Strauss and Walder, 1988;Peters et al, 1991;Rudzki-Small et al, 1989;Braslavsky and Heibel, 1992). Thus, the equation describing the optoacoustic signal amplitude of a sample Hs has to be extended to account for AVr,…”

Electrochemically Induced Characteristic Luminescence of Metal Ions at Anodic Valve Metal Oxides

“…This is attributed to the presence of H20 molecules in the direct surroundings of the Mn 2+ ion. 39 The origin of the luminescence of the d1~ is complicated. In oxides and halides the assignment dgs-d TM often is used, but in other cases metal-to-ligand charge transfer (MLCT) and ligand-to-metal charge transfer (LMCT) assignments are used.…”