Disclosed is a method for manufacturing crystals of aluminates of one or more element(s) other than aluminium, referred to as “A. The method includes: placing starting reagents, including at least one aluminium element source and a source of the element(s) A that has a degree of oxidation of between 1 and 6, in suspension in a liquid medium, forming a suspension referred to as the “starting suspension”; milling the starting suspension at ≤50° C., in a three-dimensional liquid medium ball mill for ≤5 minutes; recovering, at the outlet of the three-dimensional ball mill, a suspension referred to as the “end suspension” including the starting reagents in activated form or crystals of aluminate of the element(s) A generally in hydrated form; if required, calcination of the end suspension when it includes the starting reagents in activated form, to obtain generally non-hydrated crystals of aluminate of the element(s) A.

Improvements in methods for manufacturing glow in-the-dark targets are disclosed. This provides an ink that produces images that will glow in the dark for an extended period of time after the ink has been exposed to natural or artificial light. This can be used for flexographic printing, offset printing, gravure printing, and screen printing applications. The ink includes a phosphorescent pigment and optionally includes a colorant on a substrate of paper, plastic or metal. The phosphorescent pigment material is not coated prior to mixing with other ink components. The pigment material has a particle diameter size of about 600 mesh to about 1500 mesh. The ink includes a colorant (optional), a thermoplastic resin binder, a charge-controlling agent, a release agent, as well as the phosphorescent pigment.

A phosphor may have the empirical formula: (AB).sub.1+x+2yAl.sub.11−x−y(AC).sub.xLi.sub.yO.sub.17:E, where 0<x+y<11; x>0; AC=B, Ga, In, or combinations thereof; AB=Na, K, Rb, Cs, or combinations thereof; and E=Eu, Ce, Yb, Mn, or combinations thereof. The phosphor may be used in conversion LED components.

A fluorescent material has a core-shell structure. The core contains a crystal phase of an inorganic compound having Formula: MxMgaAlyOzNw (A); M represents a metal; x satisfies 0.001≤x≤0.3; a satisfies 0≤a≤1.0−x; y satisfies 1.2≤y≤11.3; z satisfies 2.8≤z≤18; and w satisfies 0≤w≤1.0. The shell is formed on at least a part of a surface of the core and contains boron and/or silicon. The core has a tetrahedral site occupancy of M1 of 0.032 or more and a specific surface area of 0.01 to 4.1 m.sup.2/g. A ratio Y/X of a peak area value Y of boron or silicon to a peak area value X of M present in the shell satisfies 0<Y/X≤0.095 when EDX measurement of a cross section of the fluorescent material is performed.

A light emitting device includes a light emitting element, and a fluorescent member including a phosphor. The light emitting device satisfies any of Condition (A): a correlated color temperature of light emission of the light emitting device is within a range of 4500 K or more and 7500 K or less, a content of a first phosphor is within a range of 29 mass % or more and 90 mass % or less, and a melanopic ratio is within a range of 1.0 or more and 1.4 or less; Condition (B): a correlated color temperature of light emission of the light emitting device is within a range of 2500 K or more and less than 4500 K, a content of a first phosphor is within a range of 25 mass % or more and 90 mass % or less, and a melanopic ratio is within a range of 0.7 or more and 1.1 or less; and Condition (C): a correlated color temperature of light emission of the light emitting device is within a range of 2500 K or more and 3000 K or less, a content of a first phosphor is within a range of 20 mass % or more and 90 mass % or less, and a melanopic ratio is within a range of 0.48 or more and 1.10 or less.

An audio sound is detected. The audio sound is determined to be indicative of a power source of a safety sensor waning. Based on the determination, first light is produced based on a reaction of one or more chemicals with second light from a light emitting diode (LED), wherein the first light supplements the second light.

A phosphor having an elemental composition represented by the following composition formula: Sr.sub.yMg.sub.(1-x) M.sub.xAl.sub.zO.sub.(1+y+1.5z) (1), in the formula (1), M represents at least one metal element selected from the group consisting of manganese, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, thulium, and ytterbium, x represents a value of 0.01≤x≤0.8, y represents a value of 1≤y≤2, and z represents a value of 10≤z≤22, wherein the phosphor has a specific surface area of less than 2.7 m.sup.2/g.

A phosphor having an elemental composition represented by the following composition formula: Sr.sub.yMg.sub.(1−x)M.sub.xAl.sub.zO.sub.(1+y+1.5z) (1), in the formula (1), M represents at least one metal element selected from the group consisting of manganese, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, thulium, and ytterbium, x represents a value of 0.01≤x≤0.8, y represents a value of 1≤y≤2, and z represents a value of 10≤z≤22, wherein a full width at half maximum of an XRD peak at 2θ=31.7°±0.5 is less than 0.207.

The purpose of the present invention is to provide a mechanoluminescent material which can be exhibit brighter luminescence compared to traditional SAO mechanoluminescent material even with respect to small strains and which has a relatively high mechanoluminescent capability even when left to stand for a long period of time after excitation. Provided is a strontium aluminate mechanoluminescent material containing Zr ions, characterized in that the Zr ions are contained in a reduced state, the content of the Zr ions is 10 mol % or less, and in a thermoluminescence measurement, one or more luminescence peaks are observed at a temperature of 100° C. or higher.

Provided are a method of producing an aluminate fluorescent material, an aluminate fluorescent material and a light emitting device. The production method includes heat-treating a mixture prepared by mixing a compound containing at least one alkaline earth metal element selected from the group consisting of Ba, Sr and Ca, a Mg-containing compound not acting as a flux, a Mn-containing compound, an Al-containing compound, a first flux containing at least one alkali metal element selected from the group consisting of Na, K, Rb and Cs, and a Mg-containing second flux to give an aluminate fluorescent material.