Process for producing bi-based oxide superconductor single crystals
US5369090A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1993 |
| Grant date | Nov 29, 1994 |
| Priority date | — |
| Expiry date | Apr 15, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC30B13/00
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A process for producing Bi-based oxide superconductor single crystals by the floating zone method is disclosed, which comprises using a feed rod of an oxide comprising a formulation of metallic elements represented by the following general formula: EQU Bi.sub.p Sr.sub.q Ca.sub.r Cu.sub.2 O.sub.y wherein EQU 2.00< p< 2.18, 1.87< q< 2.00, 0.9.ltoreq. r.ltoreq. 1.0, and y is a positive number, in a moving rate of said rod of from 0.1 to 0.35 mm per hour in the side where crystals are accumulated, in which preferably, in the initial stage of the formation of crystals, the diameters of the rod-like crystals to be accumulated are changed in the wavelike state, and more preferably, in the middle stage of the subsequent formation of crystals, the amount of change thereof is gradually decreased. According to the present invention, the deposition of different phases which inhibit the growth of crystals and the formation of fine pores can be eliminated, and the constitutional supercooling during the growth of crystals can be avoided. Therefore, large-size Bi-based oxide super-conductor single crystals having a good quality can be produced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.