A single crystal composition includes an alkali halide crystal doped with a divalent element in the amount of 0.5 to 5 weight percent, the doped crystal having an optical transmission of at least 45% at at least one wavelength. An alkali halide doped with at least one of europium and ytterbium is particularly useful as a scintillator.

A halide material, such as scintillator crystals of LaBr.sub.3:Ce and SrI.sub.2:Eu, with a passivation surface layer is disclosed. The surface layer comprises one or more halides of lower water solubility than the scintillator crystal that the surface layer covers. A method for making such a material is also disclosed. In certain aspects of the disclosure, a passivation layer is formed on a surface of a halide material such as a scintillator crystal of LaBr.sub.3:Ce of SrI.sub.2:Eu by fluorinating the surface with a fluorinating agent, such as F.sub.2 for LaBr.sub.3:Ce and HF for SrI.sub.2:Eu.

A scintillator includes CsBr.sub.xI.sub.(1-x) doped with Europium (CsBr.sub.xI.sub.(1-x):Eu) wherein x<0.5, and is obtained by annealing CsBr.sub.xI.sub.(1-x):Eu material at a temperature from 50 C. to 280 C. The EPR spectrum of the obtained scintillator measured at room temperature at a frequency of 34 GHz shows a maximum signal height at a magnetic field of 1200 mT, and the signal height at 1090 mT and 1140 mT does not exceed 40%, wherein the normalized signal height percentage at 1200 mT is calculated to be 100%. The scintillator is useful in a high energy radiation detection and radiography imaging apparatus.

A wavelength conversion filter, includes: a wavelength conversion layer in which a wavelength conversion material is dispersed in a transparent resin base material; and an ultraviolet absorption layer which is provided on the surface of the wavelength conversion layer and in which an ultraviolet absorber is dispersed in a transparent resin base material, wherein the wavelength conversion layer contains 0.01 to 30 parts by mass of the wavelength conversion material with respect to 100 parts by mass of the transparent resin base material included in the wavelength conversion layer.

Metal halide scintillators are described. More particularly, the scintillators include Tl and/or In-based ternary metal halides, such as those of the formulas A.sub.2BX.sub.4 and AB.sub.2X.sub.5, wherein A is an alkali metal, such as Li, Na, K, Rb, Cs or any combination thereof; B is an alkali earth metal, such as Be, Mg, Ca, Sr, Ba or any combination thereof; X is a halide, such as Cl, Br, I, F or any combination thereof; some or all of A has been replaced by Tl and/or In, and some or all of B has been replaced by another dopant, such as Eu, Ce, Tb, Yb, and Pr. Radiation detectors comprising the metal halide scintillators are also described.

A process for treating a luminescent halogen-containing material includes contacting the luminescent halogen-containing material with an atmosphere comprising a halogen-containing oxidizing agent for a period of at least about two hours. The luminescent halogen-containing material has a composition other than (i) A.sub.x[MF.sub.y]:Mn.sup.4+, where A is Li, Na, K, Rb, Cs, or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is the absolute value of the charge of the [MF.sub.y] ion; and y is 5, 6 or 7; (ii) Zn.sub.2[MF.sub.7]:Mn.sup.4+, where M is selected from Al, Ga, In, and combinations thereof; (iii) E[MF.sub.6]:Mn.sup.4+, where E is selected from Mg, Ca, Sr, Ba, Zn, and combinations thereof; and where M is selected from Ge, Si, Sn, Ti, Zr, and combinations thereof; or (iv) Ba.sub.0.65Zr.sub.0.35F.sub.2.70:Mn.sup.4+

Metal halide scintillators are described. More particularly, the scintillators include doped (e.g., europium-doped) ternary metal halides, such as those of the formulas A.sub.2BX.sub.4 and AB.sub.2X.sub.5, wherein A is an alkali metal, such as Li, Na, K, Rb, Cs or any combination thereof; B is an alkali earth metal, such as Be, Mg, Ca, Sr, Ba or any combination thereof; and X is a halide, such as Cl, Br, I, F or any combination thereof. Radiation detectors comprising the novel metal halide scintillators and other ternary metal halides, such as those of the formulas A.sub.2EuX.sub.4 and AEu.sub.2X.sub.5, wherein A is an alkali metal and X is a halide, are also described.

The present invention relates to metal halide colloidal nanoparticles represented by a following Chemical Formula 1 and a method for producing the same:
A.sub.3MX.sub.6[Chemical Formula 1] wherein in the Chemical Formula 1, A is an alkali metal element, M is a rare-earth metal element, and X is a halogen element.

The present invention aims at providing a scintillator for high temperature environments which has satisfactory light emission characteristics under high temperature environments; and a method for measuring radiation under high temperature environments. The scintillator for high temperature environments comprises a colquiriite-type crystal represented by the chemical formula LiM.sup.1M.sup.2X.sub.6 (where M.sup.1 is at least one alkaline earth metal element selected from Mg, Ca, Sr and Ba, M.sup.2 is at least one metal element selected from Al, Ga and Sc, and X is at least one halogen element selected from F, Cl, Br and I), for example, typified by LiCaAlF.sub.6, and the crystal optionally containing a lanthanoid element such as Ce or Eu. The method for measuring radiation under high temperature environments uses the scintillator.

A single crystal composition includes an alkali halide crystal doped with a divalent element in the amount of 0.5 to 5 weight percent, the doped crystal having an optical transmission of at least 45% at at least one wavelength. An alkali halide doped with at least one of europium and ytterbium is particularly useful as a scintillator.