U.S. Philips Corporation

John M Robertson

Antonius B Voermans

John C Brice

Dirk J Breed

Maurits W Van Tol

Piet F Bongers

Bernardus A Van Bakel

John E Davies

A device for propagating magnetic domains includes a monocrystalline nonmagnetic substrate of a rare earth gallium garnet bearing a layer of an iron garnet capable of supporting local enclosed magnetic domains. The iron garnet layer is grown in compression on a (100) face of the nonmagnetic substrate. The iron garnet comprises manganese in part of the iron sites of its crystal lattice, and comprises yttrium and at least one representative selected from the group comprising bismuth and the rare earth metals in the dodecahedral lattice sites. Such a magnetic garnet has a very high uniaxial anisotropy and a high domain mobility. These properties make the device extremely suitable for propagating submicron magnetic domains having diameters as small as 0.4 .mu.m.

Device for propagating magnetic domains

A device for propagating magnetic domains, comprising a monocrystalline nonmagnetic substrate of a material having a garnet structure, and a layer of an iron garnet grown epitaxially on the nonmagnetic substrate. In the dodecahedral lattice sites, the iron garnet comprises at least a bismuth ion and a rare-earth ion selected from the group consisting of lutetium, thulium, and ytterbium. Such a magnetic garnet combines very high uniaxial anisotropy with a high domain mobility, which properties make the device extremely suitable for the propagation of magnetic domains having diameters from approximately 1 to approximately 2 .mu.m under the influence of comparatively low driving fields.

A luminescent screen consisting of one self-supporting monocrystalline body and having a luminescent surface layer with V-shaped grooves. Such screens may be exposed to radiation having a larger energy than was usual so far with phosphor screens and have a very large luminous efficiency. In addition the resolving power is very large since there are no particles with limiting dimensions. Such screens may be used for displaying very bright pictures suitable for projection on a projection screen.

Luminescent screen

A method of growing monocrystalline bismuth rare earth iron garnet, either as a single crystal or as an epitaxial layer, from a solution containing composing components of the garnet together with a flux. The flux consists essentially of a mixture of Bi.sub.2 O.sub.3 and RO.sub.2, wherein R is at least one of the elements Si, Ge, Ti, Sn, Zr, Ce and Te, wherein the system Bi.sub.2 O.sub.3 --RO.sub.2 includes a eutectic composition having a eutectic temperature which is below the melting temperature of pure Bi.sub.2 O.sub.3. By using these Bi.sub.2 O.sub.3 --RO.sub.2 fluxes, the monocrystalline garnets produced have lower optical absorption coefficients at, for example 5100 A and 5600 A than similar garnets grown using lead-containing fluxes. Furthermore higher growth rates and higher growth temperatures are possible when using the Bi.sub.2 O.sub.3 --RO.sub.2 fluxes rather than lead-containing fluxes.

Method of growing single crystals of rare earth metal iron garnet

A method of growing a monocrystalline bismuth rare earth iron garnet material from a melt in which a flux containing bismuth oxide and an alkali metal oxide is employed.

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Eindhoven, Netherlands

John M Robertson