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dc.contributor.authorHall, Monte Rossen
dc.date.accessioned2016-02-01T14:44:56Zen
dc.date.available2016-02-01T14:44:56Zen
dc.date.issued1968en
dc.identifier.urihttp://hdl.handle.net/10919/64582en
dc.description.abstractAn electron microprobe equipped with a device for making luminescence measurements has been used to determine the concentration of luminescence activators in zoned cassiterites of hydrothermal origin. Micron-scale growth zones contain variable amounts of Ti, Fe, W and other impurities. The impurity ions replace Sn⁴⁺ to produce luminescence centers. The relative intensity of cathodoluminescence and the amount and kind of impurity activators were simultaneously measured while scanning the growth zones with a micro-focussed electron beam. Two distinct emission bands were observed, a yellow-green (λ ~ 565 mµ) band for Ti-activation and a blue (λ ~ 440 mµ) band for W-activation. Measurements made on a heated sample show strong thermal quenching of the Ti-activated cathodoluminescence. The decay time for the Ti-activated emission, which is independent of temperature from 21°c to 275°C, is 0.168 msec. The cathodoluminescence spectrum for W-activation closely resembles that of self-activated CaWO₄ (Leverenz, 1946) although a higher oxygen coordination (VI) for W in cassiterite is to be expected, Fe occurring with Ti appears to enhance the Ti-activated emission. Fe occurring with W or Si quenches luminescence.en
dc.format.extent78 leavesen
dc.format.mimetypeapplication/pdfen
dc.language.isoen_USen
dc.publisherVirginia Polytechnic Instituteen
dc.relation.isformatofOCLC# 6754235en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject.lccLD5655.V855 1968.H335en
dc.subject.lcshCassiteriteen
dc.subject.lcshLuminescenceen
dc.titleAn electron microprobe study of luminescence centers in cassiteriteen
dc.typeThesisen
dc.contributor.departmentGeological Sciencesen
dc.description.degreeMaster of Scienceen
thesis.degree.nameMaster of Scienceen
thesis.degree.levelmastersen
thesis.degree.grantorVirginia Polytechnic Instituteen
thesis.degree.disciplineGeological Sciencesen
dc.type.dcmitypeTexten


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