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Preparation of Gamma Fe(2)O(3) Films and Applications

IP.com Disclosure Number: IPCOM000081258D
Original Publication Date: 1974-Apr-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Ahn, KY: AUTHOR [+4]

Abstract

A magnetic disc is made using Gamma Fe(2)O(3) as the magnetic storage medium that is deposited on a substrate, in that Gamma Fe(2)O(3) has good magnetic properties, is stable and is corrosion resistant.

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Preparation of Gamma Fe(2)O(3) Films and Applications

A magnetic disc is made using Gamma Fe(2)O(3) as the magnetic storage medium that is deposited on a substrate, in that Gamma Fe(2)O(3) has good magnetic properties, is stable and is corrosion resistant.

In order to construct the disc, a nonsingle-crystal substrate, such as glass, on which a thin film of vanadium or chromium is deposited. The latter metals very closely match the lattice constants of magnetite (Fe(3)O(4)). By employing low- temperature oxidation in mixed gases of O(2) and H(2)O, where the temperature range is 200-300 degrees C, Fe(3)O(49 is converted to Gamma Fe(2)O(3), without removing the magnetic film from the substrate that will be the ultimate support for the Gamma F(2)O(3) magnetic film. Another way of making the FeO film is to sputter or evaporate Gamma Fe(2)O(3) or Fe(3)O(4), in a partial pressure of H(2)O and/or O(2), onto a substrate that is precoated with a thin layer of Fe(3)O(4), the latter serving as a nucleation layer to enhance the growth of Gamma Fe(2)O(3). Such nucleation occurs while the temperature of the substrate is maintained at or below 300 degrees C.

It is known that Gamma Fe(2)O(3) can be made in particle form, but such particles do not lend themselves to being made in thin film form. Moreover, when Gamma Fe(2)O(3) has been grown by vapor epitaxial growth, the substrate has had to be limited to a single crystal; the latter restriction limits the size of the magnetic are...