A Study of Sulfur and Phosphorus Distribution in a Single Crystal of Refractory Alloy by Transmission Electron Microscopy and MXRSA

AbstractX-ray diffraction (XRD) line-broadening analysis has been used to determine dislocation densities in zirconium alloys with hexagonal closepacked (hep) crystal structures and a complex distribution of dislocations reflecting the plastic, anisotropy of the material. The validity of the technique has been assessed by comparison with direct measurements of dislocation densities in deformed polycrystalline and neutron-irradiated single crystal material using transmission electron microscopy (TEM). The results show that-there is good agreement between the XRD and TEM for measurements on the deformed material whereas there is a large discrepancy for measurements on the irradiated single crystal; the XRD measurements significantly underestimating the TEM observations.

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Characterization of spray-pyrolized superconducting YBaCuO thin films on single-crystal MgO by transmission electron microscopy

Journal of Materials Research ◽

10.1557/jmr.1990.1605 ◽

1990 ◽

Vol 5 (8) ◽

pp. 1605-1611 ◽

Cited By ~ 11

Author(s):

S. J. Golden ◽

H. Isotalo ◽

M. Lanham ◽

J. Mayer ◽

F. F. Lange ◽

...

Keyword(s):

Electron Microscopy ◽

Thin Films ◽

Transmission Electron Microscopy ◽

Film Thickness ◽

Single Crystal ◽

Processing Parameters ◽

Transmission Electron ◽

Film Substrate ◽

Mgo Substrate

Superconducting YBaCuO thin films have been fabricated on single-crystal MgO by the spray-pyrolysis of nitrate precursors. The effects on the superconductive behavior of processing parameters such as time and temperature of heat treatment and film thickness were investigated. The superconductive behavior was found to be strongly dependent on film thickness. Films of thickness 1 μm were found to have a Tc of 67 K while thinner films showed appreciably degraded properties. Transmission electron microscopy studies have shown that the heat treatments necessary for the formation of the superconductive phase (for example, 950 °C for 30 min) also cause a substantial degree of film-substrate interdiffusion. Diffusion distances for Cu in the MgO substrate and Mg in the film were found to be sufficient to explain the degradation of the superconductive behavior in films of thickness 0.5 μm and 0.2 μm. From the concentration profiles obtained by EDS analysis diffusion coefficients at 950 °C for Mg into the YBaCuO thin film and for Cu into the MgO substrate were evaluated as 3 × 10−19 m2/s and 1 × 10−17 m2/s, respectively.

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Epitaxy of Nb3 Sn Films on Sapphire

MRS Proceedings ◽

10.1557/proc-37-517 ◽

1984 ◽

Vol 37 ◽

Cited By ~ 1

Author(s):

A. F. Marshall ◽

F. Hellman ◽

B. Oh

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Film Thickness ◽

Single Crystal ◽

Domain Structure ◽

High Temperatures ◽

Defect Structure ◽

Epitaxial Relationship ◽

Crystal Matrix ◽

Transmission Electron

AbstractFilms of Nb3Sn vapor deposited at low rates and high temperatures on (1102) sapphire form an epitaxial <100> single crystal matrix with a domain structure of misoriented regions bounded by low-angle dislocation boundaries. Nucleation of other orientations at the interface result in a highly oriented but polycrystalline film through approximately the first thousand Angstroms of film thickness. After this point random orientations become overgrown by epitaxial <100> regions. At slightly lower temperatures many small <100> grains with a second epitaxial relationship also nucleate at the interface. These rotated grains persist through greater thicknesses than random orientations. The misorientation defect structure of the single crystal matrix is analyzed by transmission electron microscopy.

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