Abstract: Shaped articles, e.g., bars, of semiconductor-grade, ultra-pure silicon, are facilely and efficiently produced by thermally decomposing/pyrolyzing a monosilane feedstream on a red-heated silicon support member, whereby high purity silicon is deposited thereon, and thence recycling the majority of the by-product reaction admixture into said monosilane feedstream.

Abstract: Shaped articles, e.g., bars, of semiconductor-grade, ultra-pure silicon, are facilely and efficiently produced by thermally decomposing/pyrolyzing a monosilane feedstream on a red-heated silicon support member, whereby high purity silicon is deposited thereon, and then recycling the majority of the by-product reaction admixture into said monosilane feedstream.

Abstract: A powder of elemental silicon having high purity and a density in excess of about 0.6 g/cm.sup.3, preferably ranging from 0.8 to 1.2 g/cm.sup.3, and which is non-amorphous as determined by X-ray analysis, is facilely prepared by thermally decomposing a silane feedstream at a decomposition reaction temperature ranging from 500.degree. to 700.degree. C., preferably from 500.degree. to 600.degree. C.

Abstract: Novel alloys comprising neodymium, iron and optionally another rare earth metal are facilely prepared by reducing a neodymium/rare earth halide with a reducing metal, in the presence of iron.

Abstract: Additive composition for an acid copper electroplating bath, which bath being well adapted for the copper plating of printed circuits, is comprised of (1) the sodium salt of .omega.-sulfo-n-propyl N,N-diethyldithiocarbamate, (2) polyethylene glycol having an average molecular weight ranging from about 6,000 to 20,000, (3) crystal violet, and (4) sulfuric acid.

Abstract: Gallium oxide, Ga.sub.2 O.sub.3, well adapted for the manufacture therefrom of garnets, luminophors, and the like, is prepared by (i) admixing, under stirring, a solution of a gallium salt with a base to convert said salt into gallium hydroxide, Ga(OH.sub.3 ; (ii) aging said gallium hydroxide reaction medium at elevated temperatures to effect precipitation therefrom of a gallium oxide/hydroxide fraction, GaO(OH); (iii) next filtering said gallium oxide/hydroxide fraction from said precipitation medium; (iv) drying and (v) calcining said filtered precipitate to convert same into said gallium oxide, Ga.sub.2 O.sub.3, with said oxide/hydroxide fraction (vi) being washed either before or after said filtration step (iii).

Abstract: A process for the manufacture of a polycrystalline garnet containing aluminium and/or gallium and/or indium and at least one element taken from the group comprising the rare earths and yttrium, and to the corresponding monocrystal.

Abstract: A process for the manufacture of a polycrystalline garnet and to the corresponding monocrystal.The process comprises the following steps:(1) a solution containing the salts of the constituent cations of the garnet, in the proportions corresponding to the composition of the latter, is prepared;(2) corresponding hydroxides are co-precipitated by means of a base in order to obtain a co-hydroxide;(3) if appropriate, the co-hydroxide is left to age;(4) it is filtered off;(5) it is washed;(6) it is dried; and(7) it is then calcined at a temperature above the temperature for the formation of the desired garnet structure.The monocrystals obtained by Czochralski drawing of the polycrystalline garnets of the invention can be used, in particular, as substrates in magnetic bubble memory devices.