Ambient dependence of visible emissions in SrTiO3
Abstract We investigated the visible emission property of SrTiO3 (STO) single crystals with high temperature annealing in some ambient conditions. We found that the green emission in STO, which should be associated with intermediate states originating from functional ionic defects inside the samples, such as cation/oxygen vacancies, showed strong ambient dependence. While high temperature annealing in the O2 atmosphere suppressed the intensity of visible emission, annealing in an O2-free atmosphere, such as N2 or H2, increased it. The broad visible emissions were fitted with three sub-modes, whose intensities showed different evolutions with respect to the ambient condition. Our study demonstrated the systematic development of defect states with the amount of the oxygen vacancies in STO.
Abstract Radicals generated in autoxidized methyl oleate, linoleate and linolenate have been detected by ESR and ENDOR using the spin trap 2-methyl-2-nitrosopropane, this being the first report of ENDOR spectra on such systems.