USA As Represented by Secretary of the Navy

Mohammad Fatemi

Mark E Twigg

Laverne S Birks

Bijan Tadayon

Richard L Henry

Daniel D Koleske

Alma E Wickenden

An electronic device characterized by a 10-300 micron thick sapphire crystal substrate having a polished off a-plane growth surface, a 10-1000 angstrom thick nucleating layer disposed on the substrate for promoting film growth thereon, and a 0.1-10 micron thick semiconducting film disposed on the nucleating layer.

Electronic devices grown on off-axis sapphire substrate

An amorphous compound is changed to single crystal structure by heating at an elevated temperature in an inert atmosphere or in an atmosphere of a forming gas, the amorphous compound is composed of at least one Group III-A element of the Periodic Table and at least one Group V-A element, the amorphous compound having an excess over stoichiometric amount of at least one Group V-A element. The single crystal phase compound, intrinsically doped with at least one element from Group V-A, has the properties of high conductivity for a semiconductor without using any extrinsic dopant and a non-alloyed ohmic contact with a metal.

Method for intrinsically doped III-A and V-A compounds

Intrinsically doped III-A and V-A compounds having precipitates of V-A

A method of measuring the lattice parameter in an unknown single crystal by omparing its diffraction angle to a standard single crystal, on a double-crystal diffractometer is disclosed. The method comprises several steps including mounting the unknown and standard crystals on a mounting block of the second stage of a double-crystal diffractometer aligning a tilt axis of the crystal surface with an x-ray beam and the azimuth axis of the second stage crystal mount, rotating the mounting block until the normals of the crystals have equal vertical components, tilting the crystal about the azimuth axis until the crystal normals are in line with the x-ray beam measuring the angle of the sharpest diffraction peak from each crystal while moving the crystals laterally across the beam, rotating the crystal mounting block assembly by 180 degrees about the azimuth axis while maintaining the relative tilt between the two wafers, such that the same area of the crystal surface remains in the x-ray beam during the 180 degrees rotation, sequentially measuring the angle of sharpest diffraction peak of both crystals after rotation, and calculating the diffraction angle of the unknown crystal from the standard crystal diffraction angle by using the diffraction angles measured before and after rotation by 180 degrees and thereby removing any misorientation of the crystal normals in the horizontal plane. A novel device for performing the tilt corrections of the crystals is also disclosed.

High resolution technique and instrument for measuring lattice

Apparatus for providing remote-operated two dimensional translation in a tical plane in an accurate and reliable manner for use in a laboratory sampling system, comprises two translation stages with a moveable slide affixed to one of such stages, mounted so as to be independently translatable in orthogonal directions in the vertical plane and are coupled to an integral drive system in such a manner so as to result in a compact unit.

Remotely operated, X-Y translation slide with stationary motors

A multi-electrode grid for aligning polarized particles such as asbestos hin a dielectric medium.

Multielectrode grid for aligning polarized particles such as asbestos

A system for identifying chrysotile asbestos as well as other asbestiform bers in air pollution samples which comprises a collimated x-ray beam which is incident on parallel aligned asbestos fibers. Diffracted x-rays are detected by a proportional counter set at the diffraction line position for the (002) plane. Background intensity may be detected by a second counter set above the axis, or the sample may be rotated 90.degree. and the one detector used to detect diffracted and background x-rays.

Parallel-beam X-ray optics for measuring asbestos

A method of forming parallel aligned chrysotile asbestos fibers on a thin bstrate for use in a system for identifying the chrysotile asbestos in air pollution samples. The system comprises a collimated x-ray beam which is incident on the parallel aligned asbestos fibers. Diffracted x-rays are detected by an adjustable proportional counter set at the diffraction line position for the (002) plane. Background intensity may be detected by a second adjustable counter set above the axis at the same angle 2.theta., or the sample may be rotated 90.degree. and the one detector used to detect diffracted and background x-rays.

Growing community of inventors

McLean, VA, United States of America

Mohammad Fatemi