Characterization of Nb3Sn diffusion layer (A-15) material

Author

Diadiuk, V. ; Bostock, J. ; MacVicar, M.L.A.

Author_Institution

Lincoln Lab., M.I.T., Lexington, MA, USA

Volume

15

Issue

1

fYear

1979

fDate

1/1/1979 12:00:00 AM

Firstpage

610

Lastpage

612

Abstract

Microstructural characterization of Nb3Sn diffusion layers grown by Sn-vapor reaction with single crystal Nb substrates has been carried out using Auger and X-ray spectroscopy, X-ray and reflection electron diffractometry, and scanning electron microscopy. The layers exhibit preferred crystallographic orientation traceable to the underlying Nb-substrate orientation. The $\\langle 111 \\rangle$ -Nb-substrate layers differ substantially from all other-Nb-direction layers. In particular, they exhibit surface-like composition profiles over several hundred angstroms into the bulk, a very rough micro-structure including numerous microcracks, and a surface superconducting transition temperature of < 1 K. Non- $\\langle 111 \\rangle$ -Nb-substrate layers with 1 μm columnar grain structure and surface Tc\´s ∼ 18 K appear to have breaking stresses far in excess of bulk polycrystalline Nb3Sn.

Keywords

Superconducting materials; Crystal microstructure; Crystallography; Niobium; Reflection; Rough surfaces; Scanning electron microscopy; Spectroscopy; Surface roughness; Tin; X-ray diffraction;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.1979.1060219

Filename

1060219