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12. Characteristics of emission centers in alkali feldspar: a new approach by using cathodoluminescence spectral deconvolution

Author

Kayama, Masahiro, Nakano, Satoshi, and Nishido, Hirotsugu

Subjects
Alkali feldspar -- Properties, Iron -- Properties, Syenite -- Properties, Earth sciences
Abstract

Alkali feldspars in syenite from the Cerro Balmaceda pluton in the Patagonian Andes, Chile, show various petrographic microtextures formed during the magmatic to high-and low-temperature hydrothermal stages in which cathodoluminescence (CL) shows a wide range of blue, violet, and pink to red colors with variable brightness. Their CL spectra exhibit two emission bands: one at 405-420 nm in the blue region and the other at 700-760 nm in the red-infrared (IR) region. Asymmetrically shaped spectral peaks in energy units suggest overlapping of each individual emission, which corresponds to various luminescence centers. Blue emission bands were separated into two spectral peaks fitted by Gaussian curves centered at 3.055-3.076 and 2.815-2.845 eV. A positive correlation is found between emission intensities at 3.055-3.076 eV and Ti[O.sub.2] contents, suggesting the activation of a [Ti.sup.4+] impurity as an emission center. The intensities at 2.815-2.845 eV, where clear and featureless feldspar (CF; not affected by hydrothermal metasomatism) is shown under optical microscopy, which have intensities appreciably higher than those showing patched microperthite (PMP), formed during low-temperature hydrothermal reactions, correlate reciprocally with the intensities of red-IR emission caused by a [Fe.sup.3+] impurity center. The peak at 2.815-2.845 eV can be attributed to oxygen defects associated with Al-O-Al and Al-O-Ti bridges. Most of the areas show CL emissions at 700-760 nm in the red-IR region, in which intensities increase with an increase in Fe203 contents as impurities. The [Fe.sup.3+] ion acts as an activator for the red-IR emission. The Ab-rich and Or-rich phases of PMP have emission components at 1.644 eV (754 nm) and 1.727 eV (717 nm), respectively. The red-IR emission from CF consists of emission components at 1.677 eV (739 nm) and 1.557 eV (796 nm), according to an [Fe.sup.3+] impurity center in the Or-rich phase and in the Ab-rich phase as cryptoperthite, respectively. Both components are centered at a wavelength longer than the emission band of Ab-rich and Or-rich phases of PMP, suggesting a change in configurational state around the [Fe.sup.3+] ion from the T2 to the T1 site by low-temperature hydrothermal metasomatic reactions. Accordingly, the peak positions of the red-IR emission are controlled by the ordering state of [Fe.sup.3+] ion into the T I site, the existence of multiphase perthite and chemical composition. Keywords: Cathodoluminescence, alkali feldspar, [Ti.sup.4+] center, Al-[O.sup.-]-A1 center, oxygen defects associated with Al-O-Al and A1-O-Ti bridges, [Fe.sup.3+] center, hydrothermal metasomatic reaction, cathodoluminescence spectral deconvolution DOI: 10.2138/am.2010.3427

Published
2010

13. Cathodoluminescence characterization of tridymite and cristobalite: effects of electron irradiation and sample temperature

Author

Kayama, Masahiro, Nishido, Hirotsugu, and Ninagawa, Kiyotaka

Subjects
Irradiation -- Methods, Cristobalite -- Properties, Cathodoluminescence -- Research, Earth sciences
Abstract

Cathodoluminescence (CL) spectra of tridymite and cristobalite have broad peaks around 430 and 400 nm, respectively, both of which can be assigned to the [[Al[O.sub.4]/[M.sup.+]].sup.0] defect. The CL intensities of these spectral peaks in the blue region decrease with prolonged exposure to electron irradiation, similar to the short-lived luminescence observed in quartz, although quartz shows a lower decrease in CL intensity compared to these minerals. Cristobalite has a higher CL intensity reduction rate during irradiation than does tridymite. Irradiation of these minerals at low temperatures results in a more rapid decay of CL emission, whereas that of quartz shows no apparent change in the rate of CL emission at similar temperatures. Confocal micro-Raman spectroscopy of the electron irradiated surface of these minerals reveals the amorphization caused by the interaction of the electron beam with the surface layer to a depth of several micrometers. This suggests that such structural destruction diminishes the activity of CL emission centers related to the [[Al[O.sub.4]/[M.sup.+]].sup.0] defects by migration of monovalent cations associated with exchanged Al in the tetrahedral sites. Both samples present a considerable reduction of their CL intensities at higher temperature, suggesting a temperature quenching phenomenon. The activation energy in the quenching process was evaluated by a least-squares fitting of the Arrhenius plots, assuming the Mott-Seitz model. The result implies that the energy of non-radiative transition in this process might be transferred to lattice vibrations as phonons in two different manners. This might be related to different irradiation responses of the CL with a change in sample temperature. Keywords: Tridymite, cristobalite, cathodoluminescence, electron irradiation, temperature quenching, Raman spectroscopy

Published
2009

18. Complex thermal and schock history of the Juvinas eucrites

Author

Kanemaru, Rei, Yamaguchi, Akira, and Nishido, Hirotsugu

Abstract

第8回極域科学シンポジウム/個別セッション：[OA] 南極隕石12月7日（木）国語研究所 2階講堂The Eighth Symposium on Polar Science/Ordinary sessions: [OA] Antarctic meteoritesThu. 7 Dec./2F Auditorium, National Institute for Japanese Language and Linguistics

Published
2017

19. Cathodoluminescence color-zoning in the enstatite chondrite of Yamato 86004

Author

Ohgo, Syuhei, Mishima, Maki, Endo, Minoru, Ninagawa, Kiyotaka, and Nishido, Hirotsugu

Abstract

第8回極域科学シンポジウム/個別セッション：[OA] 南極隕石12月6日（水）国語研究所 2階講堂The Eighth Symposium on Polar Science/Ordinary sessions: [OA] Antarctic meteoritesWed. 6 Dec./2F Auditorium, National Institute for Japanese Language and Linguistics

Published
2017

24. 熱ルミネッセンス法による鉱物・岩石の衝撃変成の研究

Author

Ninagawa, Kiyotaka, Nishido, Hirotsugu, Okumura, Tasuku, and Yamanaka, Chihiro

Abstract

平成18年度スペースプラズマ研究会 (2007年3月22日-23日. 宇宙航空研究開発機構宇宙科学研究本部(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, Space Plasma Conference FY2006 (March 22-23, 2007. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000114009

Published
2006

25. Luminescence Spectroscopical Properties of Plagioclase Particles from the Hayabusa Sample Return Mission: An Implication for Study of Space Weathering Processes in the Asteroid Itokawa

Author

Gucsik, Arnold, primary, Nakamura, Tomoki, additional, Jäger, Cornelia, additional, Ninagawa, Kiyotaka, additional, Nishido, Hirotsugu, additional, Kayama, Masahiro, additional, Tsuchiyama, Akira, additional, Ott, Ulrich, additional, and Kereszturi, Ákos, additional

Published
2017
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38. Cathodoluminescence microscopy and spectroscopy of forsterite from Kaba meteorite: An application to the study of hydrothermal alteration of parent body

Author

Gucsik, Arnold, primary, Endo, Taro, additional, Nishido, Hirotsugu, additional, Ninagawa, Kiyotaka, additional, Kayama, Masahiro, additional, Bérczi, Szaniszló, additional, Nagy, Szabolcs, additional, Ábrahám, Péter, additional, Kimura, Yuki, additional, Miura, Hitoshi, additional, Gyollai, Ildikó, additional, Simonia, Irakli, additional, Rózsa, Péter, additional, Posta, József, additional, Apai, Dániel, additional, Mihályi, Krisztián, additional, Nagy, Mihály, additional, and Ott, Ulrich, additional

Published
2013
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50. Zeolites in the Granitic Rocks of Chugoku District, Southwest Japan

Author

WAKISAKA, Hiroshi, NISHIDO, Hirotsugu, YOSHIASA, Akira, KITAGAWA, Ryuji, and TAKENO, Setsuo

Abstract

Ca-zeolites such as laumontite, stilbite and chabazite were found in the granitic rocks of both magnetite and ilmenite series of late Cretaceous to Tertiary age developed widely in the Chugoku district. These zeolites occur (1) in veins of various scale, (2) replacing plagioclase of the host granitic rocks, and (3) in pegmatitic druse. Mineralogy were investigated by X-ray powder diffraction method, the optical microscope, the scanning electron microscopy and the electron microprobe. Based on the mode of occurrence and the associated minerals, laumontite and stilbite in veins and replacing plagioclases are concluded to be formed from hydrothermal solutions filling open fractures which have been formed under the paleo-stress field after the solidification stage of the host granitic rocks. Probable formation condition of laumontite and stilbite was estimated as follows; 200-250°C(temperature), 0.5-1.0 Kb(P total) and 20-40 bar(max Pco ).

Published
1994

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