The present invention provides an optically functional material comprising a rare-earth complex represented by the formula (I) ##STR1## wherein M is a rare-earth atom, n.sub.1 is 2 or 3, n.sub.2 is 2, 3 or 4, R is a C.sub.1 -C.sub.20 group containing no H, X is a Group IVA atom, Group VA atom other than nitrogen or Group VIA atom other than oxygen, n.sub.3 is 0 or 1, and Y is C-Z' (wherein Z' is D, a halogen or C.sub.1 -C.sub.20 group containing no H), N, P, As, Sb or Bi, or by the formula (II) ...

Compositions of the formula GdMn.sub.1.sub.-x Fe.sub.x Si where 0<x.ltoreq.0.5 or LnMnSi where Ln is at least one of Gd, La or Y can be made by heating stoichiometric amounts of the elements or composition of two or more thereof. The compositions are magnetic with Curie temperatures in the range 275.degree.-330.degree.K. and can be used in thermally activated magnetic switches.

A rare earth magnet alloy including, by weight, 8 to 20% of Sm, 6 to 20% of one or more of elements selected from the group consisting of Nd, Pr and Y, 10 to 25% of Fe, 5 to 10% of Cu, 0.1 to 1% of Ti, 1 to 4% of Zr, 0.1 to 1.0% of Mn, 0.003 to 0.015% of B, optional amount of Ce and the balance of Co, in which the total sum for the amount of Nd, Pr, Y and Ce and the amount of Sm is from 22 to 28%. P and/or S may be added instead of or together with B. The magnet alloy has the coercive force of g...

The present rare gas fluorescent lamp can prevent reduction of an effective light-emitting region by securely suppressing creeping discharge even when a conductive material is provided to improve starting performance. The rare gas fluorescent lamp having a light-emitting tube whose inner surface is coated by a fluorescent material and which is filled with a rare gas, a plurality of external electrodes which are provided on an outer surface of the light-emitting tube, a conductive material, which...

A rare earth magnet having excellent corrosion resistance is provided. It has a magnet body (10) containing a rare earth element, and a protective film (20) formed on the magnet body (10). In the protective film (20), a first protective film (21), a second protective film (22) and a third protective film (23) are laminated in this order from the side of the magnet body (10). These are in a polycrystalline state and composed of a metal plated film, for example. The first protective film (21) and ...

Rare earth glass-polishing compositions of improved homogeneity and reproducibility are prepared by (a) simultaneously continuously admixing a cerium salt solution, a basic solution and a solution of at least one acid and/or one salt, the anion or anions of which being adopted to form insoluble rare earth compounds, the number of equivalents of base being equal to or greater than the number of equivalents of cerium, and the pH of the reaction medium being greater than about 6; (b) filtering the ...

Rare earth hydroxides are recovered from the rare earth ores, e.g., monazite, xenotime and/or bastnasite, by treating the ore with an aqueous solution of an alkali metal hydroxide, under agitation and essentially constant pressure, at a temperature of from about 100.degree. to 220.degree. C., and wherein the ratio by weight of alkali metal hydroxide/ore ranges from about 1.4 to 0.5, e.g., a weight ratio of sodium hydroxide/ore of from about 1 to 0.5, or a weight ratio of potassium hydroxide/ore ...

The rare earth borides are prepared at relatively low temperatures by reacting a rare earth halide with elemental boron in the presence of a reducing amount of aluminum metal.

A rare earth permanent magnet of the formula in which R is rare earth element(s) and/or Y, M is Si, Ti, Mo, B, W, V, Cr, Mn, Al, Nb, Ni, Sn, Ta, Zr, and/or Hf, and x, y, z are numbers such that and in which the matrix cells consist of two finely segregated phases.

Highly purified rare gas (helium, neon, argon, krypton, xenon, etc.) is obtained by removing impurities contained therein, such as nitrogen, hydrocarbon, carbon monoxide, carbon dioxide, oxygen, hydrogen and water, at relatively low temperatures by the use of a getter. This getter is a two-component alloy of zirconium and vanadium, or a multi-component alloy containing, as well as zirconium and vanadium, at least one of chromium, nickel and cobalt.