THE GROWTH OF SINGLE CRYSTALS OF DOPED AND UNDOPED YTTRIA AND YTTRIUM ALUMINATE IN A HOLLOW CATHODE ZONE REFINER.
Abstract
The objective of this work is the preparation of yttria and yttrium aluminate monocrystals by a hollow cathode float-zone technique. It will be recalled that this growth procedure involves the direct crystallization from a surface tension supported molten zone of the same material. The successful application of the hollow cathode discharge technique to a float-zone growth process requires the solution of three major problems: (1) The hollow cathode discharge must be controlled to give a molten zone which is sufficiently localized to permit the achievement of surface tension support throughout the crystal growth operation; (2) A means of minimizing the thermal gradients on the growing crystal must be provided to inhibit thermal fracture; and (3) A technique for the preparation of suitable feed rods employed in the growth process must be established.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 15, 1966
- Accession Number
- AD0802169