THE GROWTH OF RARE EARTH OXIDE, GARNET AND ALUMINATE SINGLE CRYSTALS BY A HOLLOW CATHODE FLOAT-ZONE PROCESS.

Abstract

The crystal growth of yttrium aluminum garnet, yttrium aluminate and yttrium oxide was carried out under this program. Large garnet crystals could be successfully grown only from feed rods where a quantity of aluminum oxide was added in excess of the 3Y2O3:5Al2O3 stoichiometric ratio. Both doped and undoped garnets were prepared from the alumina-rich preparation. Yttrium aluminate crystals, on the other hand, were grown from stoichiometric 1Y2O3:1Al2O3 feed rod compositions. The problems of metastability, as well as incongruence in melting, were eliminated in this compound by the addition of 1Nd2O3:1Al2O3 which also served as the crystal dopant. Yttrium oxide crystals were also grown using differential feed rod scanning to compensate for evaporation losses from the molten zone. In the doped garnet, yttrium aluminate and yttrium oxide, crystal quality was limited by cracking. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1969
Accession Number
AD0686077

Entities

People

  • Walter Class

Tags

DTIC Thesaurus Topics

  • Aluminates
  • Aluminum
  • Aluminum Oxides
  • Crystal Growth
  • Crystals
  • Garnet
  • Oxides
  • Single Crystals
  • Yttrium
  • Yttrium Aluminum Garnet
  • Yttrium Oxides

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.