Laser-excited Luminescence Research Articles

Impurities effects on the U6+luminescence in LiF

A complex investigation including various methods (luminescence, absorption, laser excited luminescence, EPR) has been performed to elucidate the nature of U6+luminescent centres in LiF. By varying the preparation conditions, especially co-doping with cations or OH-, several centres have been isolated. EPR data on U5+in gamma -irradiated crystals sustain uranate structures for all of them. Models for three luminescent U6+centres are proposed. It is concluded that in the authors' pure crystals there is a basic structure, the completely charge compensated (UO5F)5-complex (emission at 5185 AA and 5278 AA). Impurities or defects can associate to it, producing other centres. Cationic impurities promote also a different type of uranate complex, (UO6)6-.

Energy transfer in YAlG:Nd codoped with Ce

Laser excited luminescence has been used to study an energy transfer between Ce3+ and Nd3+ ions in YAlG:Nd,Ce laser crystal with varying small Ce concentrations. Radiative Ce3+→Nd3+ energy transfer dominates in the studied single crystal samples but this process can also be accompanied by multistep transfer mechanisms (for example by (Ce3+→Ce3+)n→ Nd3+ transfer mechanism). The Ce3+→Nd3+ radiative energy transfer improves pumping of green and yellow excitation lines in YAlG:Nd,Ce laser rods because the contribution of the additional transfer pumping of Nd3+ ions from Ce3+ ions is more than three times greater than should be expected from concentration differences between Nd and Ce. This favourable behaviour is explained from high quantum efficiency of Ce3+ emission and higher Ce3+ absorption cross sections in comparison with the Nd3+ ones (more than one order of magnitude difference).

THE E1 - E1 + Δ1 TRANSITIONS IN BULK GROWN AND IN IMPLANTED LASER ANNEALED HEAVILY DOPED GERMANIUM : LUMINESCENCE

We report the observation of cw laser-excited visible luminescence at the E1 - E1, + Δ1 direct gaps in n-type Ge with Ne >≈ 1018 cm-3 . The phenomenon appears to be induced by participation of the high density of free electrons in the E1 - E1 + Δ1 transitions at the L-point (2.1 and 2.3 eV) since the luminescence is not observed in either pure or p-type Ge. We have used this luminescence to investigate the effect of doping on the band structure of bulk doped and also of phosphorus implanted laser annealed Ge. Shifts and broadening of the E1 - E1 + Δ1 energies and also Burstein-Moss-Fermi energy shifts have been observed. The results for bulk Ge go over smoothly and overlap with the results for the laser annealed material.

Lanthanide complexes of ionophores. Laser-excited luminescence spectroscopy of bis(4,5-dimethyl-N,N,N',N'-tetrapropyl-3,6-dioxaoctanediamide)europium(III) tetrafluoroborate

Synthese et caracterisation du bis (dimethyl-4,5 N,N,N',N'-tetrapropyl dioxa-3,6 octanediamide) europium(III) tetrafluoroborate par spectrometrie luminescence a laser, a l'etat solide et en solution

Laser-excited luminescence and absorption study of monomer and cluster tetracyanopalladate(II) species in mixed crystals

Laser-excited luminescence and absorption study of monomer and cluster tetracyanopalladate(II) species in mixed crystals

Laser excited luminescence and optical absorption studies of interacting tetracyanoplatinate ions in crystals, pellets, and frozen aqueous solutions

The optical properties of interacting tetracyanoplatinate(II) ions in different environments have been studied by laser excited luminescence, optical absorption, and magnetic circular dichroism. We have examined Pt(CN)4 -2 ion interactions in mixed crystals of alkali halides and alkali cyanides, pure single crystals of the barium and potassium salts, pellets, and in frozen aqueous solutions of different concentrations. Luminescence spectra of mixed alkali halide crystals indicate the presence of dimer and Pt(CN)4 -2 cluster entities in the lattice. Site selective spectroscopy has been used to demonstrate the presence of various sites. Pressed KBr pellets of salts of the Pt(CN)4 -2 ion have been found to contain chains of Pt(CN)4 -2 anions. Frozen aqueous solution studies for a range of concentrations of the Pt(CN)4 -2 ion have allowed us to identify the dimer and cluster spectra with time resolved and lifetime measurements. Optical absorption and magnetic circular dichroism spectra have been compared with MO models for the Pt(CN)4 -2 ion in different environments in order to make electronic assignments.

Laser-excited luminescence study of the chain compound barium tetrakis(cyano-C)palladate tetrahydrate

Laser-excited luminescence study of the chain compound barium tetrakis(cyano-C)palladate tetrahydrate

On the detection of fingerprints by laser excited luminescence

Two surveys were carried out to determine the percentage of latent fingerprints detectable by their inherent luminescence under laser illumination. Less than one-fifth of 240 samples each containing four prints on paper gave luminescent prints. The luminescence from these was weak and only detectable under close scrutiny. Similar results were obtained for 120 samples each containing one print on glass. Forty-one of the samples showing no luminescence were sprayed, approximately one month after deposition, with a solution containing the fluorescent tagging agent 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD chloride). After treatment with NBD chloride, 37 of these samples gave luminescent prints, many of which were intensely luminescent and contained good ridge detail.

Kinetics of laser excited luminescence and photovoltage in AgCl crystals

Kinetics of laser excited luminescence and photovoltage in AgCl crystals

Dye laser probing of primary C2 radicals formed by IR intense field photolysis of ethylene

The C2-radicals in the lower electronic statea 3 II u have been studied by the method of laser-excited luminescence of products of ethylene IR photolysis. The dependence of C2-radical concentration on IR field power density and its time evolution have been investigated. The threshold characteristics of C2-radical occurrence and the ratio between excited and unexcited radicals have been determined. Different mechanisms for their formation are being discussed.

ChemInform Abstract: EXAMINATION OF PHOTOPHYSICS IN CHROMIUM(III) COMPLEXES BY LASER‐EXCITED LUMINESCENCE

Chemischer InformationsdienstVolume 6, Issue 50 Organoelement Compounds ChemInform Abstract: EXAMINATION OF PHOTOPHYSICS IN CHROMIUM(III) COMPLEXES BY LASER-EXCITED LUMINESCENCE W. M. WATSON, W. M. WATSONSearch for more papers by this authorYU. WANG, YU. WANGSearch for more papers by this authorJAMES T. YARDLEY, JAMES T. YARDLEYSearch for more papers by this authorGALEN D. STUCKY, GALEN D. STUCKYSearch for more papers by this author W. M. WATSON, W. M. WATSONSearch for more papers by this authorYU. WANG, YU. WANGSearch for more papers by this authorJAMES T. YARDLEY, JAMES T. YARDLEYSearch for more papers by this authorGALEN D. STUCKY, GALEN D. STUCKYSearch for more papers by this author First published: December 16, 1975 https://doi.org/10.1002/chin.197550330AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume6, Issue50December 16, 1975 RelatedInformation

Examination of photophysics in rare earth chelates by laser-excited luminescence

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTExamination of photophysics in rare earth chelates by laser-excited luminescenceW. M. Watson, Richard P. Zerger, James T. Yardley, and Galen D. StuckyCite this: Inorg. Chem. 1975, 14, 11, 2675–2680Publication Date (Print):November 1, 1975Publication History Published online1 May 2002Published inissue 1 November 1975https://doi.org/10.1021/ic50153a016RIGHTS & PERMISSIONSArticle Views176Altmetric-Citations35LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (848 KB) Get e-Alerts Get e-Alerts

Examination of photophysics in chromium(III) complexes by laser-excited luminescence

Examination of photophysics in chromium(III) complexes by laser-excited luminescence

High temperature luminescence spectra from F-centers in CaO

Experimental and theoretical investigations of the high temperature behavior of F-Centers in additively colored CaO crystals have resulted in the identification of the 1 T 1 u → 1 A 1 g emission process. Laser-excited luminescence spectra were measured from 50–350°C, and the emission band attributed to the 1 T 1 u → 1 A 1 g transition shifted to higher energies and increased in intensity with increasing temperature relative to the luminescence band of the 3 T 1 u → 1 A 1 g transition.

Stimulated Emission and Excited States of the I6 Donor Electron in ZnO

Laser-excited luminescence has been measured in ZnO at 1.2°K. Emission due to the annihilation of the I6 bound excition with simultaneous excitation or ionization of the donor electron has been observed in stimulated emission, which was excited by intense N2 laser light. From the hydrogenlike series of these emission lines, the binding energy and the effective mass of the donor electron are estimated to be 40 meV and 0.22m, respectively.