Abstract: A method is described for adjusting magnetic properties of iron-containing magnetic films. The coercivity of magneto-optic films such as bismuth garnet films is adjusted by an annealing method which comprises reduction with a reducing agent such as H.sub.2 followed by oxidation using an oxidizing agent such as O.sub.2 and/or O.sub.3 to adjust to required coercivity levels with the sequence of reduction followed by oxidation repeated one or more times to obtain required coercivity. It is also an aspect of the invention to precede the first reducing treatment with an oxygen annealing step to enhance uniformity of the switching field.

Abstract: A bistable single crystal magneto-optic film of preselected coercivity is described. The film is readily switchable and is characterized by a substantially square shaped hysteresis loop. The film properties are attributed to controlled introduction in the film of defects of predetermined size and distribution. Defects of from about 0.4 .mu.m to about 4.0 .mu.m present in numbers per cm.sup.2 of from about 10 to about 10.sup.6, with optimal distribution falling in the range of from about 100 to about 1000, are described. Also described are methods of achieving the required defect size and distribution utilizing procedures such as ion bombardment, particle abrasion/deposition, laser ablation or annealing of the film or substrate upon which the film is supported. Devices in which the films can be used to advantage, such as flaw detecting, imaging and microwave processing, are described.

Abstract: A calcium yttrium silicate oxyapatite laser crystal doped with thulium provides a laser material finding particular utility in 2 .mu.m diode pumped lasers. The calcium yttrium silicate oxyapatite doped with trivalent thulium, preferably has the formulaCa(Tm.sub.x Y.sub.1-x).sub.4 (SiO.sub.4).sub.3 O, where x=0.0025-0.12.

Abstract: A method of forming an epitaxial layer of an oxidic high T.sub.c superconductor on a substantially lattice matched monocrystalline substrate is described. The film is formed by liquid phase epitaxy utilizing a melt containing a nutriment composed of oxides of each element of the oxidic superconductor and a non-oxidic flux for such oxides. The preferred flux is an alkali halide. The monocrystalline substrate on which the film is dsposited is introduced into the melt and an epitaxial layer of oxidic superconductor is formed on the substrate.

Abstract: Monocrystalline lanthanum orthogallate compositions grown along a predetermined crystallographic direction in the form of a single crystal of a size greater than 1 cm in diameter/width and at least 10 cm in length are described. Such compositions include mixed crystal monocrystalline lanthanum orthogallates wherein a portion of the lanthanum is replaced with a rare earth element of smaller ionic radius than lanthanum and/or a portion of the gallium is replaced with Al, Sc or In. The foregoing monocrystalline compositions are particularly suited as superconductor substrates.

Abstract: A thin film superconducting device is described in which the substrate is a single or mixed single crystal of lanthanum orthogallate grown from a pure melt of lanthanum, gallium and additive oxides. A portion of the gallium single crystal can be replaced by Sc, Al or In and/or a portion of the lanthanum can be replaced by a rare earth element of smaller ionic radius than lanthanum to allow for manipulation of the lattice constant.

Abstract: Doped lanthanum orthogallate laser materials produced in the form of large perovskite-type doped single crystals are disclosed. Doped single crystals of lanthanum orthogallate are grown from a pure melt of lanthanum oxide, gallium oxide and dopant oxide while controlling the major crystallographic direction of solidification. Dopants are selected from the rare earth series elements, first transition series elements and actinide series elements.

Abstract: Monocrystalline lanthanum orthogallate grown along a predetermined crystallographic direction in the form of a single crystal of a size greater than 1 cm in diameter/width and at least 10 cm in length is described. Also described is a class of perovskite type monocrystalline compositions which are readily grown from a pure melt along a predetermined crystallographic direction. Such perovskite-type monocrystalline compositions have the following formulae:LaGa.sub.1-x Sc.sub.x O.sub.3 1.LaGa.sub.1-x Al.sub.x O.sub.3 2.LaGa.sub.1-x In.sub.x O.sub.3 3.wherein x=0.001 to 0.5. Additionally described is a class of perovskite-type monocrystalline compositions of the following formula:R.sub.x La.sub.1-x GaO.sub.3wherein R is a rare earth element of smaller ionic radius than La and wherein x=0.001 to 0.5. Further described is a class of perovskite-type monocrystalline compositions of the following formulae:R.sub.x La.sub.1-x Ga.sub.1-y Al.sub.y O.sub.3R.sub.x La.sub.1-x Ga.sub.1-y Sc.sub.y O.sub.3R.sub.x La.sub.1-x Ga.

Abstract: The invention relates to a two step method of manufacturing a magnetically switchable magneto-optic element comprising compressed bismuth-containing garnet film of low anisotropy field value deposited on a monocrystalline gadolinium garnet substrate. The first step involves growing a compressed bismuth-containing garnet film having a growth and strain induced effective anisotropy field of about 3000 gauss or less on a monocrystalline gadolinium garnet substrate. The second step involves reducing the anisotropy field of the resulting garnet film to a predetermined lower anisotropy field by ion implantation.

Abstract: The invention relates to a magnetically switchable magneto optic composite comprising an epitaxial film supported on a non-magnetic garnet substrate. The film is a bismuth-containing film which is in compression, contains a combination of cations providing a net negative magneto-strictive coefficient, has a positive value anisotropy field, a low collapse field and high figure of merit. The film is easily switchable utilizing z-y coincident drive lines and the composite can readily be formed into a chip comprising an array of switchable optically active pixels. Also disclosed are light valves, optical printers, microwave signal processors and magneto-optic light deflectors comprising the described magneto-optic light composites.

Abstract: A method for reducing the radial temperature gradient of a radiant energy emitting heated body is described. The method comprises insulating such heated body with a refractory insulating material containing an efficient absorber of the radiant energy emitted by said heated body. Specifically, materials containing trivalent dysprosium are disclosed as suitable thermal insulation for use where the heated body is at a temperature in the 1800.degree. C.-2500.degree. C. range. Also described is a crystal growth chamber for pulling unicrystalline compositions from a melt utilizing the Czochralski technique. The chamber is characterized by the placement of a refractory insulating material containing an efficient absorber of near infrared radiation around a crucible which contains the melt. Dysprosium is specifically disclosed as an efficient absorber of the near infrared radiation which is emitted by melt and crucible at the elevated temperatures employed for boule formation utilizing the Czochralski technique.