Structural Properties of Nb3Sn Diffusion Layers Fabricated on Single Crystal Nb Substrates.
Abstract
The structural properties of Nb3Sn diffusion layers fabricated on oriented single crystal Nb substrates exhibit systematic behaviors based on substrate orientation which result from interactions between the substrates and A15 overlayers. Preferred orientation of the diffusion layers is confirmed by X-ray and electron diffraction measurements. Within the bulk of a specific Nb(hkl) substrate layer, the preferred orientation appears to be a function of layer thickness for the range of thicknesses studied (or 1 to 17 micrometers). It is believed to develop over distance due to a competition between the growth region orientation at the advancing interface (required by lattice registry of the bcc and A15 lattices) and the tendency of Nb3Sn layers toward a natural growth direction, A15(100); this competition is moderated by in situ annealing of the Nb3Sn as growth advances. Consistent with this model is the fact that surface preferred orientation of a diffusion layer on a given Nb(hkl) substrate, both for as-grown surfaces and for internal surfaces exposed by etching, appears to be a function of net layer thickness.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 04, 1979
- Accession Number
- ADA074738
Entities
People
- James Frederick Debroux