Microstructural effects on the superionic conductivity of a lithiated glass-ceramic

Successful retrieval of the television camera and other components from the Surveyor III spacecraft by the Apollo 12 astronauts has provided a unique opportunity to study the effects of a known and relatively extensive exposure to the lunar environment. Microstructural effects including those produced by micro-meteorite impact, radiation damage (by both the solar wind and cosmic rays) and solar heating might be expected in the materials used to fabricate the spacecraft. Samples received were in the form of 1 cm2 of painted unpainted aluminum alloy sheet from the top of the camera visor (JPL Code 933) and the sides (935,936) and bottom (934) of the lower camera shroud. They were prepared for transmission electron microscopy by first hand-grinding with abrasive paper to a thickness of 0.006". The edges were lacquered and the sample electropolished in 10% perchloric methanol using the “window” method, to a thickness of ~0.001". Final thinning was accomplished by polishing 3 mm punched disks in an acetic-phosphoric-nitric acid solution.

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Low-temperature annealing of YBa2Cu3O7-x

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100120849 ◽

1992 ◽

Vol 50 (1) ◽

pp. 88-89

Author(s):

R.L. Sabatini ◽

Yimei Zhu ◽

Masaki Suenaga ◽

A.R. Moodenbaugh

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Low Temperature ◽

Oxygen Diffusion ◽

Diffusion Rate ◽

Oxygen Depletion ◽

Low Temperature Annealing ◽

Transmission Electron ◽

Microstructural Effects ◽

Oxygen Diffusion Rate

Low temperature annealing (<400°C) of YBa2Cu3O7x in a ozone containing oxygen atmosphere is sometimes carried out to oxygenate oxygen deficient thin films. Also, this technique can be used to fully oxygenate thinned TEM specimens when oxygen depletion in thin regions is suspected. However, the effects on the microstructure nor the extent of oxygenation of specimens has not been documented for specimens exposed to an ozone atmosphere. A particular concern is the fact that the ozone gas is so reactive and the oxygen diffusion rate at these temperatures is so slow that it may damage the specimen by an over-reaction. Thus we report here the results of an investigation on the microstructural effects of exposing a thinned YBa2Cu3O7-x specimen in an ozone atmosphere using transmission electron microscopy and energy loss spectroscopy techniques.

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Crystallization sequence of an A1N-Y2O3-SiO2 glass-ceramic

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143808 ◽

1986 ◽

Vol 44 ◽

pp. 446-447

Author(s):

T.R. Dinger ◽

G. Thomas

Keyword(s):

High Temperature ◽

Glass Ceramic ◽

Crystallization Behavior ◽

High Stress ◽

Crystallization Sequence ◽

Sio2 Glass ◽

Structural Applications ◽

Ceramic Precursors

The use of Si3N4, alloys for high temperature, high stress structural applications has prompted numerous studies of the oxynitride glasses which exist as intergranular phases in their microstructures. Oxynitride glasses have been investigated recently in their bulk form in order to understand their crystallization behavior for subsequent Si3N4 applications and to investigate their worth as glass-ceramic precursors. This research investigates the crystallization sequence of a glass having a normalized composition of Y26Si30Al11 ON11 and lying in the A1N-Y2O3-SiO2 section of the Y-Si-Al-O-N system. Such glasses exist as intergranular phases in the technologically important Y2O3/Al2O3-fluxed Si3N4 alloys.

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