Observation of the Photoinduced Conductivity in a Regular Domain Structure with Tilted Walls in MgO:LiNbO3 at a Wavelength of 632.8 nm at Bragg Diffraction

A 632.8-nm radiation-induced change in the conductivity of a regular domain structure (RDS) formed in a 5% MgO:LiNbO₃ crystal has been detected for the first time. As a result, the relaxation rate for the Bragg diffraction efficiency on the RDS, which is observed after the application of an external electric field, increases with the intensity of a probe beam. This dependence is linear in the initial stage of relaxation caused by the screening of the external field because of the redistribution of charges over tilted conductive domain walls of the RDS. For the probe beam with an intensity of 49 mW/mm², the induced effective conductivity of the RDS, which is estimated as σ_eff = 3.5×10⁻⁹Ω⁻¹m⁻¹, is more than four orders of magnitude higher than the dark conductivity of the single-domain MgO:LiNbO₃ sample.

     

Synthesis of Environmentally Safe Antiwear Additives to Lubricating Materials: State of the Art and Prospects

Russian Journal of Applied Chemistry - The review deals with the development and production of synthetic additives to lubricating oils and plastic lubricants, influencing the friction and wear of...     

Photoprocess in AgBr microcrystals in the presence of Pt(II) and Pd(II) complex ions

Results of a systematic study of the chemical sensitization of cubic-faceted AgBr emulsion microcrystals with complex compounds K₂[XY₄] and Na₆[XZ₄] [X = Pd, Pt; Y = Br^?, Cl^?, SCN^?; Z =(SO₃)_2?] were considered. The role of secondary dissociation of complex ions during the chemical sensitizing was established. Conditions were determined in which the compounds specified can be used as chemical sensitizers of AgBr. The effect of these complexes on the basic photographic characteristics was demonstrated.