Abstract: A method for preparing fine particles of a high brightness luminescent material improved in crystallinity; and a high brightness luminescent material prepared by the method. In an embodiment, BaMgAl10O17:Eu (BAM) as a high brightness luminescent material is prepared by a method which comprises providing an aqueous solution containing an aluminum alcoholate and water-soluble compounds of barium, magnesium and europium, adding an acid to the aqueous solution to form an acidic solution, heating the acidic solution to ca.900° C. and conducting a calcination at the temperature for a short time, and subsequently, firing the calcined product at a temperature higher than that for the calcination, for example, 1400° C. or higher. The method allows the preparation of BAM which comprises spherical fine particles having a pure phase and being improved in crystallinity, and thus is reduced in the deterioration by heat or VUV.

Abstract: A plasma display panel having its thermal degradation and VUV deterioration reduced through enhancement of the crystallinity of luminant excitable with vacuum ultraviolet radiation to thereby attain an enhancement of luminous efficiency; and a process for producing the same. The plasma display panel comprises a pair of opposite arranged substrates and, interposed therebetween, a phosphor layer that is excited with vacuum ultraviolet radiation to thereby emit light, the phosphor layer containing spherical fine particles of a luminant excitable with vacuum ultraviolet radiation. The luminant is composed only of a matrix substance and an activator and is highly pure without having any impurity phase. Accordingly, the phosphor layer can be formed while maintaining the luminance of luminant excitable with vacuum ultraviolet radiation, so that the luminescence intensity of phosphor layer can be enhanced. Thus, there can be provided a plasma display of high luminance.

Abstract: Disclosed is an electronic device having a multilayered structure consisting of (a) a substrate, (b) an electroconductive layer of lanthanum nickel oxide LaNiO3 having a perovskite structure formed on the substrate surface and (c) a dielectric layer of PZT having an oriented perovskite structure formed on the electroconductive layer. The device exhibits excellent piezoelectric effect under mechanical stress and stable hysteresis phenomenon of electric polarization under application of electric fields so that the device is useful as a stress sensor and as a memory device. A method for the preparation of the multilayered device is disclosed.

Abstract: Disclosed is a high-efficiency stress-luminescent material capable of emitting luminescence by receiving a mechanical stress such as compression, shearing and rubbing. The stress-luminescent material is an alkaline earth aluminate of a non-stoichiometric composition deficient in the content of the alkaline earth element by 0.01 to 20% by moles from stoichiometry. The efficiency of stress-luminescence emission can be further enhanced when the non-stoichiometric alkaline earth aluminate contains 0.01 to 10% by moles of rare earth metal ions or transition metal ions. The stress-luminescent material is prepared by subjecting a non-stoichiometric composite oxide of aluminum oxide and an alkaline earth oxide to a calcination treatment at 800 to 1700° C. in a reducing atmosphere.

Abstract: The present invention provides a new stress emission material that is different from the other known materials and that efficiently emits light when subjected to a mechanical external force such as a frictional force, a shear force, an impact, or a pressure. This stress emission material is configured by adding an emission center comprising one or more rare earths or transition metals that emit light when electrons excited by a mechanical force return to their normal state, to a base material comprising one or more of an oxide, a sulfide, a carbide, and a nitride each having an FeS.sub.2 structure. This material has an emission intensity that depends on stress.

Abstract: Provided by the invention is a novel synthetic inorganic triboluminescent material in the form of a powder, sintered block or thin film, of which the matrix phase is a piezoelectric crystalline material of a wurtzite structure such as zinc sulfide and the activator to serve as the center of luminescence is a transition metal element such as manganese, copper and rare earth elements in an amount of 0.01 to 10% by weight. The triboluminescent material is prepared by subjecting a powder blend of the matrix phase material and a thermally decomposable compound of the activator element first to a preparatory calcination treatment at 500 to 800.degree. C. and then, preferably in the form of a powder compact, to a second calcination treatment at 900 to 1700.degree. C., preferably, in vacuum under a sealed condition, when the material is liable to cause sublimation, or in an atmosphere of a reducing gas.