Pre-irradiation defects in “pure” MgO associated with hydrogen, carbon and peroxy configurations

Freund, Friedemann; Knobel, R.; Kathrein, H.; Wengeler, H.

doi:10.1016/0168-583x(84)90073-9

Cited by 14 publications

(3 citation statements)

References 26 publications

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“…Preliminary thermal desorption experiments on 150 eV deuterium irradiated MgO surfaces indicate several contributions to the D 2 desorption spectrum in the temperature range from 450 to 950 K. A dominant contribution was at 650 K. Taking into account the higher heating rate (3 K/s) and the shallow implantation depth this type of release might occur in the above annealing experiments at 550 K but only over short distances. Freund et al report release of hydrogen at 700 K for MgO heavily doped with OH À [11]. The formation of OD À groups during irradiation can not be excluded and thus above release may play a role in the observed vacancy clustering process.…”

Section: Vacancy Clustering and The Role Of Deuteriummentioning

confidence: 99%

Hydrogen implantation defects in MgO

Veen

Schüt

Fedorov

et al. 1999

Nuclear Instruments and Methods in Physics Research Section B:

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Deuterium and hydrogen ions with an energy of 15 keV have been implanted in virgin MgO (1 0 0) single crystals and in single crystals containing helium implantation generated microcavities. Doses were varied from 2´10 15 to 2´10 16 cm À2. The samples were annealed from room temperature to 950 K. The defects produced by hydrogen and the trapping of hydrogen at the defects were monitored by photon absorption and positron beam analysis. With this novel technique a depth distribution of defects can be determined for implantation depths from 0 to 2000 nm. The technique is very sensitive for vacancy and vacancy clusters, i.e. sites with low electron density. After 950 K annealing microcavities were observed for the 2´10 16 cm À2 dose but not for the 10 times lower dose. During annealing up to 750 K point defects are mobile but the defect clusters remain small and ®lled with hydrogen. In samples which contain already microcavities, point defects and deuterium from the deuterium irradiation are accumulated by the microcavities.

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Section: Vacancy Clustering and The Role Of Deuteriummentioning

confidence: 99%

Hydrogen implantation defects in MgO

Veen

Schüt

Fedorov

et al. 1999

Nuclear Instruments and Methods in Physics Research Section B:

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“…This is uncommon for nanoscale voids ͑bubbles͒ obtained after He implantation and annealing in metals 5 or semiconductors 1 and previously investigated ceramics such as ␣-Al 2 O 3 . [6][7][8][9][10] Then, the nanovoids are spherical and only for increased sizes ͑e.g., larger than a few tens of nm͒ they become facetted. 2,6,7 The origin of the strong tendency for faceting in the MgO system is most probably related to the high ͑Pauling's͒ ionicity of MgO.…”

mentioning

confidence: 99%

“…[6][7][8][9][10] Then, the nanovoids are spherical and only for increased sizes ͑e.g., larger than a few tens of nm͒ they become facetted. 2,6,7 The origin of the strong tendency for faceting in the MgO system is most probably related to the high ͑Pauling's͒ ionicity of MgO. The surface energy for different facets of MgO is largely determined by the polarity of the terminating plane.…”

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confidence: 99%

Rectangular nanovoids in helium-implanted and thermally annealed MgO(100)

Kooi

Veen

Hosson

et al. 2000

Applied Physics Letters

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Cleaved MgO͑100͒ single crystals were implanted with 30 keV 3 He ions with doses varying from 1ϫ10 19 to 1ϫ10 20 m Ϫ2 and subsequently thermally annealed from 100 to 1100°C. Transmission electron microscopy observations revealed the existence of sharply rectangular nanosize voids at a depth slightly shallower than the helium-implantation range. Monitoring of the defect depth profile and the retained amount of helium was performed by positron-beam analysis and neutron depth profiling, respectively.

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Electron Spin Resonance Studies of Light Sensitive Centers with Tetragonal Symmetry in CaO

Boas¹

1986

Physica Status Solidi (b)

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ASTwo centers with tetragonal symmetry and principal axes along (100) are observed by ESR in single crystals of CaO. The ESR signal intensity of both the centers is affected by visible light illumination. One center (911 = 2.0048, g 1 = 2.0007) occurs in highly colored crystals and may be associated with carbon impurities introduced during crystal growth. The other (911 = 1.99905, 91 = 1.99956) occurs in "clear" crystals after 1 MeV electron irradiation and has the characteristics of an anion-cation vacancy pair center containing one electron (i.e. a Por F: center). The g-values do not agree with those found for the same center in polycrystalline CaO but are consistent with a simple model of a perturbed F+ center.Zwei Zentren mit tetragonaler Symmetrie und Hauptachsen lLngs (100) werden mit ESR in CaO-Einkristallen beobachtet. Die ESR Signalintensitat beider Zentren wird durch Beleuchtung rnit sichtbarem Licht beeinflufit. Ein Zentrum (911 = 2,0048, 9 1 = 2,0007) erscheint in gefarbten Kristallen und kann mit Kohlenstoff-Verunreinigungen, die wahrend des Rachstums der Kristalle eingefuhrt werden, in Verbindung gebracht werden. Das andere Zentrum (911 = 1,99905, g 1 = = 1,99956) erscheint in ,,klaren" Kristallen nach 1 MeV-Elektronenbestrahlung und besitzt die Eigenschaften eines Anion-Kntion-Vakanz-Paar-Zentrums, das ein Elektron enthalt (z. B. P-oder F$-Zentrum). Die g-Werte stimmen nicht mit denen fiberein, die fiir dasselbe Zentrum in polykristallinem CaO gefunden werden, stimmen jedoch mit einem einfachen Modell eines gestorten F+-Zentrums uberein.

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Pre-irradiation defects in “pure” MgO associated with hydrogen, carbon and peroxy configurations

Cited by 14 publications

References 26 publications

Hydrogen implantation defects in MgO

Hydrogen implantation defects in MgO

Rectangular nanovoids in helium-implanted and thermally annealed MgO(100)

Electron Spin Resonance Studies of Light Sensitive Centers with Tetragonal Symmetry in CaO

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