Abstract: The silicate of magnesium and of barium, strontium or calcium of the invention is characterized in that it is in the form of a suspension of solid crystallized particles in a liquid phase, said particles having a mean size between 0.1 ?m and 1 ?m. It is prepared by spray-drying a liquid mixture comprising compounds of magnesium, of silicium and of at least one first element chosen from barium, strontium and calcium, by submitting the dried mixture to a first calcination in air and to a second calcination in a reducing atmosphere and by wet milling the calcined mixture.

Abstract: A novel type of green luminophore containing mixed rare-earth phosphates is produced from precursor particles having a mean diameter ranging from 1.5 to 15 microns; such particles have an inorganic core and a shell of a mixed lanthanum and/or cerium phosphate, optionally doped with terbium, evenly covering the inorganic core with a thickness greater than or equal to 300 nm.

Abstract: The compound according to the invention is a compound of formula (1) Ax W1-yMOyO3, wherein A is chosen from the group comprising the Li, Na, NH4, K and H cations, and it is characterised in that x and y verify the relationships 0?x?1 and 0?y?0.5, and in that it has a crystalline structure of the hexagonal type with a base of WO6 octahedra, said structure having tunnels delimited by 6, 4 and 3 of said octahedra and oriented along the axis c.

Abstract: A composition comprising an inorganic core and an aluminate shell is described. The aluminate can have the formula (1): (CeaTbb)Mg1+xAl11+y019+x+y ??(1), where a, b, x and y comply with the relations a+b=1?0.2˜x˜+0.2 and ?0.2˜y˜+0.2, wherein the shell uniformly covers the inorganic core over a thickness of no less than 300 nm. A phosphor is also described that can be obtained by calcinating the composition at a temperature of at least 1200° C.

Abstract: The composite of the invention comprises (a) a polymer selected from ethylene/vinyl acetate, polyethylene terephthalate, ethylene tetrafluoroethylene, ethylene trifluorochloroethylene, perfluorinated ethylene-propylene, polyvinyl butyral, polyurethane and silicones; (b) an inorganic phosphor based on at least one element selected from rare earth elements, zinc and manganese, which has an external quantum efficiency of greater than or equal to 40% for at least one excitation wavelength of between 350 nm and 440 nm; an absorption of less than or equal to 10% for a wavelength of greater than 440 nm; a mean particle size of less than 1 ?m; and this phosphor has an emission maximum in a range of wavelengths between 440 nm and 900 nm.

Abstract: A composition comprising an inorganic core and an aluminate shell is described. The aluminate can have the formula (1): (CeaTbb)Mg1+xAl11+yO19+x+y??(1), where a, b, x and y comply with the relations a+b=1?0.2?x?+0.2 and ?0.2?y?+0.2, wherein the shell uniformly covers the inorganic core over a thickness of no less than 300 nm. A phosphor is also described that can be obtained by calcinating the composition at a temperature of at least 1200° C.

Abstract: A composition including an inorganic core and a europium and yttrium oxide or gadolinium shell uniformly covering the inorganic core at a thickness greater than or equal to 300 nm is described. A phosphor including the composition is also described. In addition a process of forming the composition by: forming a suspension including the inorganic core with pH of 8 to 11; adding a solution including a europium salt and yttrium or gadolinium salt to the suspension and maintaining the pH of the reaction medium at a constant value; and separating the formed solid and calcining the same to a temperature of at most 1000° C. is described.

Abstract: Liquid phase suspensions of substantially monocrystalline rare-earth borate particles, the mean size thereof ranging from 100 to 400 nm, are prepared by roasting a rare earth borocarbonate or hydroxyborocarbonate at a temperature which is sufficient for forming a borate and obtaining a product whose specific surface area is equal to or greater than 3 m2/g and then wet grinding the roasted product; such borates are useful in the form of luminophors, in particular, as luminescent transparent materials.

Abstract: The phosphor of the invention is based on a lanthunum cerium terbium phosphate, and it is characterized in that the phosphate consists of particles having a mean size of at most 4 ?m, in that it has a lithium content of at most 30 ppm, a boton content of at most 30 ppm and in that it has a variation of brightness between the brightness measured on the phosphor at 25° C. and that measured on the same phosphor at 200° C. of at most 4%.

Abstract: A novel type of green luminophore containing mixed rare-earth phosphates is produced from precursor particles having a mean diameter ranging from 1.5 to 15 microns; such particles have an inorganic core and a shell of a mixed lanthanum and/or cerium phosphate, optionally doped with terbium, evenly covering the inorganic core with a thickness greater than or equal to 300 nm.

Abstract: A novel type of green luminophore containing mixed rare-earth phosphates is produced from precursor particles having a mean diameter ranging from 1.5 to 15 microns; such particles have an inorganic core and a shell of a mixed lanthanum and/or cerium phosphate, optionally doped with terbium, evenly covering the inorganic core with a thickness greater than or equal to 300 nm.

Abstract: A composition comprising an inorganic core and an aluminate shell is described. The aluminate can have the formula (1): (CeaTbb)Mg1+xAl11+yO19+x+y ??(1), where a, b, x and y comply with the relations a+b=1?0.2?x?+0.2 and ?0.2?y?+0.2, wherein the shell uniformly covers the inorganic core over a thickness of no less than 300 nm. A phosphor is also described that can be obtained by calcinating the composition at a temperature of at least 1200° C.

Abstract: Submicronic barium and magnesium aluminates, useful as phosphors, are in the form of a liquid-phase suspension of substantially monocrystalline particles having an average particle size ranging from 80 to 400 nm; such aluminates are prepared by a process that includes: providing a liquid mixture containing compounds of aluminum and of other elements that are part of the aluminate composition; drying the mixture by atomization; calcining the dried product in a reducing atmosphere and wet-grinding this product.

Abstract: A method of producing a phosphor is described in which a precursor including particles having an average diameter from 1.5 micrometers to 15 micrometers is heat-treated under a reducing atmosphere. The method can produce particles including a mineral core and a shell including a composite phosphate of lanthanum and/or cerium, optionally doped with terbium. The composite phosphate of lanthanum and/or cerium covers the mineral core uniformly over a thickness greater than or equal to 300 nm. The aforementioned heat treatment at a temperature of 1050° C. to 1150° C. and for a time period of 2 hours to 4 hours can involve the use of lithium tetraborate (Li2B4O7), which serves as a fluxing agent, in a mass quantity of at most 0.2%.

Abstract: A phosphate particle with a mean diameter of from 1.5 ?m to 15 ?m, which has an inorganic core and a shell that covers the inorganic core uniformly over a thickness of no less than 300 nm, is described. The shell can have a lanthanum cerium terbium phosphate of formula La(1-x-y)CexTbyPO4, where 0.2?x?0.35 and 0.19?y?0.22. The phosphor is produced by heat-treating a phosphate at a temperature of greater than 900° C.

Abstract: The composition of the invention is of the type comprising particles formed by a mineral core and a shell that covers the mineral core uniformly, said shell being based on a phosphate of cerium and/or of terbium, optionally with lanthanum. The composition is characterized in that it contains sodium at a concentration of at most 7000 ppm. The phosphor of the invention is obtained by calcination of the composition at at least 1000 DEG C.

Abstract: A composition of including particles that have a mineral core and a shell that uniformly covers the mineral core is described. The shell can be made of a cerium and/or terbium phosphate, or optionally with lanthanum. The composition can include potassium at a maximum potassium content of 7000 ppm. A phosphor obtained by calcining the composition at at least 1000° C. is also described.

Abstract: A composition including an inorganic core and a europium and yttrium oxide or gadolinium shell uniformly covering the inorganic core at a thickness greater than or equal to 300 nm is described. A phosphor including the composition is also described. In addition a process of forming the composition by: forming a suspension including the inorganic core with pH of 8 to 11; adding a solution including a europium salt and yttrium or gadolinium salt to the suspension and maintaining the pH of the reaction medium at a constant value; and separating the formed solid and calcining the same to a temperature of at most 1000° C. is described.

Abstract: A rare earth (Ln) phosphate is described, wherein Ln is either: (1) at least one rare earth selected from cerium and terbium, or (2) lanthanum in combination with at least one of the two above-mentioned rare earths and wherein the phosphate has a crystalline structure of the rhabdophane type or of the mixed rhabdophane/monazite type with a potassium content of 7000 ppm at most. The phosphate can be obtained by the precipitation of a rare earth chloride at a constant pH lower than 2, by calcination at a temperature lower than 500° C. and by redispersion in hot water. A phosphor obtained by the calcination of the phosphate at at least 1000° C. is also described.

Abstract: A rare earth element phosphate (Ln) is described, wherein Ln is either: (1) at least one rare earth element selected from cerium and terbium, or (2) lanthanum in combination with at least one of the above two rare earth elements, and wherein the phosphate has a crystalline structure either of the rhabdophane type with a sodium content of at most 6000 ppm, or of the monazite type with a sodium content of at most 4000 ppm. The phosphate can be obtained by the precipitation of a rare earth element chloride at a constant pH lower than 2, and then calcining and redispersing the same in hot water. A phosphor obtained by calcining the phosphate at at least 1000° C. is also described.