Abstract: A production method of high purity silver tetrafluoroborate, capable of producing silver tetrafluoroborate (AgBF4) at purity higher than the conventional, without using an organic solvent. The production method of the present invention is characterized in that the method comprises the step of: reacting silver fluoride with boron trifluoride in the presence of anhydrous hydrofluoric acid. Boron trifluoride is delivered into a solution obtained by dissolving or suspending silver fluoride in an anhydrous hydrofluoric acid solution.

Abstract: Provided is an apparatus capable of producing a fluoride crystal in a very short period of time, and a method suitable for producing a fluoride crystal using the apparatus. The apparatus comprises a chamber, a window material, and the like, and is modified such that it can evacuate air from the chamber to provide a high degree vacuum there. The apparatus further includes a crucible, which has a perforation at its bottom. The capillary portion of the perforation is adjusted to facilitate the contact of a seed crystal with a melt. By using the apparatus it is possible to stably produce high quality single crystals of fluorides in a short period of time.

Abstract: Provided is an apparatus capable of producing a fluoride crystal in a very short period of time, and a method suitable for producing a fluoride crystal using the apparatus. The apparatus comprises a chamber, a window material, and the like, and is modified such that it can evacuate air from the chamber to provide a high degree vacuum there. The apparatus further includes a crucible, which has a perforation at its bottom. The capillary portion of the perforation is adjusted to facilitate the contact of a seed crystal with a melt. By using the apparatus it is possible to stably produce high quality single crystals of fluorides in a short period of time.

Abstract: A production method of high purity silver tetrafluoroborate, capable of producing silver tetrafluoroborate (AgBF4) at purity higher than the conventional, without using an organic solvent. The production method of the present invention is characterized in that the method comprises the step of: reacting silver fluoride with boron trifluoride in the presence of anhydrous hydrofluoric acid. Boron trifluoride is delivered into a solution obtained by dissolving or suspending silver fluoride in an anhydrous hydrofluoric acid solution.

Abstract: A rare earth fluoride solid solution material (polycrystal and/or single crystal) characterized in that the material is obtained by mutually combining a plurality of rare earth fluorides having phase transitions and having different ion radii, respectively, so that the rare earth fluoride solid solution material is free of phase transitions. A rare earth fluoride solid solution material (polycrystal and/or single crystal) characterized in that the material is represented by (REyRE?1?y)F3 (0.0000<y<1.0000), wherein RE represents one or two or more selected from Sm, Eu, and Gd, and RE? represents one or two or more selected from Er, Tm, Yb, Lu, and Y. A rare earth fluoride solid solution material (polycrystal and/or single crystal) represented by MxREyRE?1?x?yFz., wherein RE is one or two or more selected from Ce, Pr, Nd, Eu, Tb, Ho, Er, Tm, or Yb, RE? is one or two or more selected from La, Sm, Gd, Dy, Lu, Y, and Sc, and M is one or more of Mg, Ca, Sr, and Ba.

Abstract: A scintillator, characterized in that it comprises crystals of Pr1-xCexF3 [wherein 0<x<0.5]. It emits a light in ultraviolet and visible regions when it is irradiated with a light or a radiation. The scintillator uses a material which exhibits improved performance with respect to the strength in light emission and to the speed in attenuation, and further is relatively easy in the growth of its crystal.

Abstract: It is aimed at providing a fluoride crystal growing method capable of controlling a shape of the crystal by a micro-pulling-down method. Fluoride crystals in shapes depending on purposes, respectively, can be grown by adopting carbon, platinum, and iridium as crucible materials adaptable to fluorides, respectively, and by designing shapes of the crucibles taking account of wettabilities of the materials with the fluorides, respectively.

Abstract: A rare earth fluoride solid solution material (polycrystal and/or single crystal) characterized in that the material is obtained by mutually combining a plurality of rare earth fluorides having phase transitions and having different ion radii, respectively, so that the rare earth fluoride solid solution material is free of phase transitions. A rare earth fluoride solid solution material (polycrystal and/or single crystal) characterized in that the material is represented by (REyRE?1-y)F3 (0.0000<y<1.0000), wherein RE represents one or two or more selected from Sm, Eu, and Gd, and RE? represents one or two or more selected from Er, Tm, Yb, Lu, and Y. A rare earth fluoride solid solution material (polycrystal and/or single crystal) represented by MxREyRE?1-x-yFz, wherein RE is one or two or more selected from Ce, Pr, Nd, Eu, Tb, Ho, Er, Tm, or Yb, RE? is one or two or more selected from La, Sm, Gd, Dy, Lu, Y, and Sc, and M is one or more of Mg, Ca, Sr, and Ba.

Abstract: It is aimed at providing a fluoride crystal growing method capable of controlling a shape of the crystal by a micro-pulling-down method. Fluoride crystals in shapes depending on purposes, respectively, can be grown by adopting carbon, platinum, and iridium as crucible materials adaptable to fluorides, respectively, and by designing shapes of the crucibles taking account of wettabilities of the materials with the fluorides, respectively.

Abstract: An apparatus for producing a fluoride crystal, which has a chamber, a window material and the like capable of dealing with the fluoride, is equipped with facilities necessary for high vacuum evacuation, and uses a crucible in which the capillary portion of the hole formed in the bottom thereof is so controlled for a seed crystal and a molten material to be easily contacted to each other; and a method for producing a fluoride crystal comprising using the apparatus. The apparatus allows the production of a single crystal of a fluoride having high quality in a extremely short time with stability.

Abstract: It is aimed at providing an analysis method of impurities (color centers) in fluoride, capable of extremely simply analyzing impurities (color centers) in fluoride. It is also aimed at providing an analysis method of impurities (color centers) in fluoride, for enabling evaluation of an effect by addition of a scavenger, before obtainment of a final single crystal. There are detected absorption peaks and the like of formed color centers and the like, by irradiating X-rays to an obtained fused material, and by measuring transmittances thereof before and after the irradiation. Based thereon, there are optimized melt conditions of a scavenger and the like, thereby enabling growth of a high purity molten raw material suitable for growth of a single crystal less in X-ray damage.

Abstract: A scintillator, characterized in that it comprises crystals of Pr1-xCexF3 [wherein 0<x<0.5]. It emits a light in ultraviolet and visible regions when it is irradiated with a light or a radiation. The scintillator uses a material which exhibits improved performance with respect to the strength in light emission and to the speed in attenuation, and further is relatively easy in the growth of its crystal.

Abstract: A method for reducing oxygen and carbon components in high-purity fluoride such as calcium fluoride and barium fluoride (a high-purity fluoride that is not limited to calcium fluoride and barium fluoride), or in rare-earth fluorides such as ytterbium fluoride and cerium fluoride used for an optical fiber, a coating material, and so on. The oxygen and carbon components contained in the high-purity fluoride are reduced by a fluorine gas treatment.

Abstract: To provide a method for reducing oxygen and carbon components in high-purity fluoride such as calcium fluoride and barium fluoride (high-purity fluoride is not limited to calcium fluoride and barium fluoride), or in rare-earth fluoride such as ytterbium fluoride and cerium fluoride used for an optical fiber, a coating material, and so on.