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Forming High Density Rare Earth Oxides for an Evaporation Source

IP.com Disclosure Number: IPCOM000092068D
Original Publication Date: 1968-Aug-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Ahn, KY: AUTHOR [+2]

Abstract

Efficient evaporation sources for magneto-optical materials are prepared for EuO film and doped EuO film. Either rare-earth oxide or oxide mixture is melted in an arc furnace by the following procedure. The rare-earth oxide or the oxide mixture is weighed. Dopants such as Ho, La, Y, Nd, and Gd are added from 5 to 10% by weight to the rare-earth oxide Eu(2)O(3). The powder charges are added to a thoroughly cleaned arc furnace. The system is pumped out and flushed with high-purity argon. Finally, the argon is allowed to reach an over-pressure of 4 pounds above the atmospheric pressure with a controlled blowoff valve. The arc is struck and the plasma is brought to the powder. Care is taken that the powder is not blown out of the hearth and that the arc is not extinguished by slowly circling the powder with a low-power arc.

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Forming High Density Rare Earth Oxides for an Evaporation Source

Efficient evaporation sources for magneto-optical materials are prepared for EuO film and doped EuO film. Either rare-earth oxide or oxide mixture is melted in an arc furnace by the following procedure. The rare-earth oxide or the oxide mixture is weighed. Dopants such as Ho, La, Y, Nd, and Gd are added from 5 to 10% by weight to the rare-earth oxide Eu(2)O(3). The powder charges are added to a thoroughly cleaned arc furnace. The system is pumped out and flushed with high-purity argon. Finally, the argon is allowed to reach an over- pressure of 4 pounds above the atmospheric pressure with a controlled blowoff valve. The arc is struck and the plasma is brought to the powder. Care is taken that the powder is not blown out of the hearth and that the arc is not extinguished by slowly circling the powder with a low-power arc. The gradual increase in power slowly heats the powder. Upon becoming conductive, a molten mass of oxide forms. The molten mass, upon cooling, becomes a solid button which is useful in form for an electron beam evaporation source.

Advantages for the sources prepared by this method are realized. A density is almost 100% in approximately one half an hour compared to a few days by prior methods. Almost two orders of magnitude better vacuum can be maintained during evaporation from the prepared sources. Doping of the oxides is achieved homogeneously. Spitting from the source is eliminate...