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Rare Earth Garnet Film Fabrication

IP.com Disclosure Number: IPCOM000092724D
Original Publication Date: 1967-Jan-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Giess, EA: AUTHOR [+2]

Abstract

Rare earth garnet films are used in optical devices because of their high magneto-optical activity. This method of manufacture of a gadolinium-iron-garnet GdIG film leads to the attainment of uniform and reproducible GdIG films.

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Rare Earth Garnet Film Fabrication

Rare earth garnet films are used in optical devices because of their high magneto-optical activity. This method of manufacture of a gadolinium-iron-garnet GdIG film leads to the attainment of uniform and reproducible GdIG films.

A substrate, on which the film is to be deposited, is precleaned by washing with a detergent, rubbing with dampened alumina polishing powder, washing with deionized water and followed by drying with lint-free paper toweling. Preferred substrates are fused silica, VYCOR* and PYREX*, or some other glass having a higher thermal expansion and which does not chemically react with the film. A solution is prepared of:

80.8 gm. of Fe(NO3)(3) x 9H(2)O

21.8 gm. of Gd(2)O(3)

25 ml. of nitric acid

10 ml. of water

0.5 gm. of citric acid.

This solution is diluted, using one part of the solution with four parts of ethyl alcohol. Several drops of the diluted solution are placed at the center of the chosen substrate. The latter is attached to a spinner that rotates the substrate at high speeds. Spinning urges the drops to run out as a thin film on top of the substrate. After spinning, the substrate is removed from its mounting and slowly heated to about 500 degrrees C for a period of up to 30 minutes. After such slow drying process, the GdIG film is fired in the range of 120 hours at a temperature of 650 degrees C to 1100 degrees C. If desired, multiple films can be deposited and dried, before the firing step takes place...