U.S. Philips Corporation

Heinrich Heitmann

Klaus Witter

Jens-Peter Krumme

Christoph Schmelzer

Reimar Spohr

Wolfgang F Tolksdorf

Klaus W Gerstenberg

Fritz Welz

Magneto-optical memory having a substrate of a material which is transparent for the visible-to-infrared spectral range, on which there are provided, in this sequence, a dielectric layer which is transparent for the visible-to-infrared spectral range and has a refractive index which is higher than the refractive index of the substrate and constitutes a diffusion barrier layer for oxygen and/or water, an in essence amorphous and/or in essence micro-crystalline magneto-optical layer with uniaxial anisotropy and a magnetic ordering temperature higher than ambient temperature and a top layer which acts as a reflection or interference layer and as a diffusion barrier layer for oxygen and/or water, the dielectric layer being a layer which is deposited from organic silicon materials by means of a PCVD process.

Magneto-optical memory and method of producing such a memory

In a magnetic layer of a magnetooptical modulator having fixed magnetic single domain areas, the areas of the layer present between the single domain areas are made electrically conductive by reduction.

Magnetooptical modulator

A magnetic layer for storing information in the form of a fixed, two-dimensional array of magnetic domains. The magnetic layer can be magnetized in either of two opposite directions normal to the plane of the layer. The walls of the domains are fixed by local gradients in the value and direction of the magnetic anistropy and in the value and direction of the magnetic exchange energy of the magnetic layer. The local gradients may be caused by a relatively high defect density at the domain wall locations, by implanting ions into the magnetic layer at the locations of the domain walls thereby causing a local expansion of the crystal lattice of the layer, and/or by etching a multiplicity of nonconnected tapering channels in and substantially perpendicular to the plane of the magnetic layer at these locations. Where tapering channels are used, the magnetic layer is provided on a substrate such that the crystal lattice constant of the magnetic layer is different from the crystal lattice constant of the substrate. In another embodiment, the local gradients can be the result of the epitaxial growth of a magnetic layer on a substrate which has a plurality of nonconnected etched channels at the domain wall locations.

Method of making a magnetic memory layer

A magnetic layer for storing information in the form of a fixed, two-dimensional array of magnetic domains. The magnetic layer can be magnetized in either of two opposite directions normal to the plane of the layer. The walls of the domains are fixed by local gradients in the value and direction of the magnetic anisotropy and in the value and direction of the magnetic exchange energy of the magnetic layer. The local gradients may be caused by a relatively high defect density at the domain wall locations, by implanting ions into the magnetic layer at the locations of the domain walls thereby causing a local expansion of the crystal lattice of the layer, and/or by etching a multiplicity of non-connected tapering channels in and substantially perpendicular to the plane of the magnetic layer at these locations. Where tapering channels are used, the magnetic layer is provided on a substrate such that the crystal lattice constant of the magnetic layer is different from the crystal lattice constant of the substrate. In another embodiment, the local gradients can be the result of the epitaxial growth of a magnetic layer on a substrate which has a plurality of non-connected etched channels at the domain wall locations.

Growing community of inventors

Rellingen, Germany

Heinrich Heitmann