Abstract: An ablation process by which fused deposits of silicon particles are accuated on a substrate of selected material in accordance with whether microclusters of spherical configurations or microfilaments of cylindrical configurations are to be fabricated. Silicon ablation is accomplished in an inert gas atmosphere with an excimer laser that generates light pulses of which the wavelength and frequency are controlled to fix the energy level thereof. The pressure of the inert gas atmosphere is also controlled in accordance with whether microclusters or microfilaments are to be fabricated.

Abstract: Uniform films deposited on substrates by laser ablation of targets are inased in size by configuring irradiated target areas as curves rather than flat surfaces. Since material ejected from the target area leaves in a direction normal to the target area, a curved surface results in the material following a trajectory which is at an acute angle to the surface of the substrate being coated. This results in a cone of ejected material which diverges, thus covering an area larger than the irradiated target area. The irradiated target area may be convex, concave or be comprised of a plurality of juxtaposed convex surfaces.

Abstract: c-axis oriented microwave quality HTSC films are deposited onto single crystals of gadolinium gallium garnet (GGG) using pulsed laser deposition (PLD) with conditions of 85 mTorr of oxygen partial pressure, a block temperature of 730.degree. C., a substrate surface temperature of 790.degree. C. and a laser fluence of 1 to 2 Joules/cm.sub.2 at the target, a laser repetition rate of 10 Hz and a target to substrate distance of 7 cm and in which the a and b lattice parameters of the GGG exhibit a mismatch of less than 2.5 percent with the a and b lattice parameters of the HTSC.

Abstract: Rare-earth alkaline metal titanates are used as buffer layers substrates, and oxygen diffusion barriers for the growth of high critical temperature superconductors, ferroelectrics, pyroelectrics and piezoelectrics.

Abstract: A superconducting film of HoBa.sub.2 Cu.sub.3 O.sub.7-x on a substrate is tained from a mixture containing stoichiometric amounts of Ho.sub.2 O.sub.3, BaCO.sub.3 and CuO powders by a method including the steps of(A) processing the powder mixture to an average particle size of about 2 to 3 .mu.m,(B) adding about three grams of the powder to about 25 cc of an organic dispersant,(C) depositing the powder in the organic dispersant on the substrate by electrophoresis in electric fields of about 100 to about 1000 volts/cm for about 3 to about 15 minutes to obtain superconducting films having a thickness of about 5 to about 25 .mu.m; and(D) sintering and annealing in oxygen.

Abstract: In the preferred embodiment a plurality of toroidally shaped magnets of slar size and configuraton are placed in a stack side-by-side in coaxial alignment. Alternate magnets in the stack are magnetized so that the magnetic dipole moment of each is oriented in the radial direction. An axial magnetized toroidal magnet is disposed between each pair of adjacent radially magnetized magnets. The magnetic orientation of the succesive toroidal magnets of the stack rotates continually in one direction in increments of 90.degree. or .pi./2 radians from the magnet at one end of the stack to that at the other end.

Abstract: A method and apparatus for pressing magnetic powder in a toroidal-shape we in a radial magnetic field. A magnetic flux is produced and carried by a die rod through the axial center of toroidally-shaped magnetic powder. An annular portion coaxially surrounding the die rod and magnetic powder is connected to a yoke member which carries the magnetic flux back to the magnetic flux producing means. This completes the magnetic circuit, and creates a radial magnetic field across the toroidally-shaped magnetic powder between the die rod and the annular portion. This radial magnetic field aligns the granules of the toroidally shaped magnetic powder during pressing.

Abstract: A method is disclosed of operating a cold-cathode-cold-reservoir thyratron for laser/radar and other systems employing high voltage and current pulses using ZrVFe as the hydrogen thyratron material. According to the method, a hydride of ZrVFe is first formed and the hydrided material then placed in the cathode structure of the thyratron. The tube is then pumped down to its operating pressure of approximately 10.sup.-3 atmospheres, the hydrided material then acting as a ballast to maintain that partial pressure of hydrogen at room temperature.

Abstract: The reversible temperature coefficient of magnetization of a permanent magnet alloy over the temperature range from -50 degrees C. to +150 degrees C. is lowered by heat treating the alloy in a noble gas atmosphere or in a vacuum by the steps of(a) heating the alloy at about 1150 degrees C. for 1.5 hours (b) quenching the alloy in ice water, (c) heating the alloy at about 940 degrees C. for 2 hours, (d) lowering the temperature to about 700 degrees C. and heating for one hour, (e) lowering the temperature to about 600 degrees C. and heating for one hour, (f) lowering the temperature to about 500 degrees C. and heating for 2 hours, and (g) lowering the temperature to about 400 degrees C. and heating for 10 hours.

Abstract: Magnetic alloys of the general formula Sm.sub.2 Cu.sub.1.6 Zr.sub.0.16 Fe.sub.3.3 Co.sub.12-x M.sub.x are provided wherein M is Mn or Cr and wherein x is a value greater than zero and less than 2.1.

Abstract: Compounds of the general formula Sm.sub.2-x RE.sub.x Co.sub.17-y Mn.sub.y are provided wherein RE is a rare earth element selected from the group consisting of erbium, dysprosium and gadolinium wherein x has a value greater than zero and less than 0.7 and wherein y has a value less than 2.1. The compounds are suitable for use as permanent magnet material in microwave/millimeter-wave traveling wave tubes (TWT's).

Abstract: The reversible temperature coefficient of magnetization of a permanent magnet alloy is lowered by (a) heating the alloy at about 1200 degrees C. for 2 hours, (b) quenching the alloy in ice water, (c) heating the alloy at about 850 degrees C. for 2 hours, (d) lowering the temperature to about 700 degrees C. and heating for one hour, (e) lowering the temperature to about 600 degrees C. and heating for one hour, (f) lowering the temperature to about 500 degrees C. and heating for one hour, (g) lowering the temperature to about 400 degrees C. and heating for four hours, and (h) lowering the temperature to about 280 degrees C. and heating for 12 hours. The method is particularly effective in lowering the reversible temperature coefficient of magnetization of the permanent magnet alloy Sm.sub.2 Cu.sub.1.6 Zr.sub.0.16 Fe.sub.3.3 Co.sub.12.