Abstract: A method for fabricating a textured single crystal including depositing pads made of metal on a surface of a single crystal. A protective layer is deposited on the pads and on the single crystal between the pads; and etching the surface with a first compound that etches the metal more rapidly than the protective layer is carried out. Processing continues with etching the surface with a second compound that etches the single crystal more rapidly than the protective layer; and etching the surface with a third compound that etches the protective layer more rapidly than the single crystal. The textured substrate may be used for the epitaxial growth of GaN, AlN or III-N compounds (i.e. a nitride of a metal the positive ion of which carries a +3 positive charge) in the context of the fabrication of LEDs, electronic components or solar cells.

Abstract: The invention relates to an inorganic scintillator material of formula Lu(2-y)Y(y-z-x) CexMzSi(1-v)M?vO5, in which: M represents a divalent alkaline earth metal and M? represents a trivalent metal, (z+v) being greater than or equal to 0.0001 and less than or equal to 0.2; z being greater than or equal to 0 and less than or equal to 0.2; v being greater than or equal to 0 and less than or equal to 0.2; x being greater than or equal to 0.0001 and less than 0.1; and y ranging from (x+z) to 1. In particular, this material may equip scintillation detectors for applications in industry, for the medical field (scanners) and/or for detection in oil drilling. The presence of Ca in the crystal reduces the afterglow, while stopping power for high-energy radiation remains high.

Abstract: A method of manufacturing a low defect density GaN material comprising at least two steps of growing epitaxial layers of GaN with differences in growing conditions, (a.) a first step of growing an epitaxial layer GaN on an epitaxially competent layer under first growing conditions selected to induce island features formation, followed by (b.) a second step of growing an epitaxial layer of GaN under second growing conditions selected to enhance lateral growth until coalescence.

Abstract: The invention relates to a method of preparing a polycrystalline block of a halide of formula AeLnfX(3f+e) in which Ln represents one or more rare earths, X represents one or more halogen atoms selected from the group consisting of Cl, Br and I, and A represents one or more alkali metals selected from the group consisting of K, Li, Na, Rb and Cs, e, which may be zero, being less than or equal to 3f, and f being greater than or equal to 1, having a low water and oxyhalide content, in which the method comprises heating a mixture of, on the one hand, at least one compound having at least one Ln—X bond and, on the other hand, a sufficient amount of NH4X in order to obtain the oxyhalide content, resulting in a molten mass comprising the rare-earth halide, the heating being followed by cooling, and the heating, after having reached 300° C., never going below 200° C. before the molten mass has been obtained.

Abstract: The invention relates to a crystalline lithium fluoride doped with at least 0.018 mol per kg of a divalent positive ion M present in the fluoride state, in particular of the single-crystal type. The ion may be Mg2+, Zn2+ or Co2+. This fluoride has a high reflectivity and intense radiation that can emanate therefrom may be effectively received by a fast light scintillator, especially of the rare-earth halide type. It is particularly useful as a monochromator for X-ray fluorescence radiation for the purpose of elemental analysis.

Abstract: A scintillator material comprises a rare-earth halide coated with a layer comprising a resin and a pigment. In an embodiment, the scintillator material is used in an ionizing-radiation detector, and in particular embodiment, a gamma camera. The layer can adhere well and act as an absorbent or reflector depending on the color of the pigment.

Abstract: The invention concerns an ionizing radiation detector comprising a housing containing: an avalanche photodiode in contact, through its photosensitive face, with the scintillator material via optical coupling, a preamplifier of the electrical signal from the avalanche photodiode. This detector is compact, portable, and very robust. It detects X-rays or gamma rays with excellent resolution, which can be less than 3% at 662 keV.

Abstract: An ionizing radiation detector comprising a housing includes a scintillator material, an avalanche photodiode in contact with the scintillator material via optical coupling, and a preamplifier.

Abstract: The invention relates to a method of preparing a polycrystalline block of a halide of formula AeLnfX(3f+e) in which Ln represents one or more rare earths, X represents one or more halogen atoms selected from the group consisting of Cl, Br and I, and A represents one or more alkali metals selected from the group consisting of K, Li, Na, Rb and Cs, e, which may be zero, being less than or equal to 3f, and f being greater than or equal to 1, having a low water and oxyhalide content, in which the method comprises heating a mixture of, on the one hand, at least one compound having at least one Ln-X bond and, on the other hand, a sufficient amount of NH4X in order to obtain the oxyhalide content, resulting in a molten mass comprising the rare-earth halide, the heating being followed by cooling, and the heating, after having reached 300° C., never going below 200° C. before the molten mass has been obtained.

Abstract: The invention relates to an inorganic scintillator material of formula Lu(2-y)Y (y-z-x) CexMzSi (1-v) M? vO5, in which: M represents a divalent alkaline earth metal and M? represents a trivalent metal, (z+v) being greater than or equal to 0.0001 and less than or equal to 0.2; z being greater than or equal to 0 and less than or equal to 0.2; v being greater than or equal to 0 and less than or equal to 0.2; x being greater than or equal to 0.0001 and less than 0.1; and y ranging from (x+z) to 1. In particular, this material may equip scintillation detectors for applications in industry, for the medical field (scanners) and/or for detection in oil drilling. The presence of Ca in the crystal reduces the afterglow, while stopping power for high-energy radiation remains high.

Abstract: The invention relates to a method of preparing a polycrystalline block of a halide of formula AeLnfX(3f+e) in which Ln represents one or more rare earths, X represents one or more halogen atoms selected from the group consisting of Cl, Br and I, and A represents one or more alkali metals selected from the group consisting of K, Li, Na, Rb and Cs, e, which may be zero, being less than or equal to 3f, and f being greater than or equal to 1, having a low water and oxyhalide content, in which the method comprises heating a mixture of, on the one hand, at least one compound having at least one Ln—X bond and, on the other hand, a sufficient amount of NH4X in order to obtain the oxyhalide content, resulting in a molten mass comprising the rare-earth halide, the heating being followed by cooling, and the heating, after having reached 300° C., never going below 200° C. before the molten mass has been obtained.

Abstract: Inorganic scintillator material of formula AnLnpX(3p+n) in which has a very low nuclear background noise and is particularly suitable as a detector scintillator for coating weight or thickness measurements, in the fields of nuclear medicine, physics, chemistry and oil exploration, and for the detection of dangerous or illicit materials.

Abstract: The invention relates to a process for manufacturing a single crystal comprising a rare-earth halide, having improved machining or cleavage behaviour, comprising heat treatment in a furnace, the atmosphere of which is brought, for at least 1 hour, to between 0.70 times Tm and 0.995 times Tm of a single crystal comprising a rare-earth halide, Tm representing the melting point of said single crystal, the temperature gradient at any point in the atmosphere of the furnace being less than 15 K/cm for said heat treatment. After carrying out the treatment according to the invention, the single crystals may be machined or cleaved without uncontrolled fracture. The single crystals may be used in a medical imaging device, especially a positron emission tomography system or a gamma camera or a CT scanner, for crude oil exploration, for detection and identification of fissile or radioactive materials, for nuclear and high-energy physics, for astrophysics or for industrial control.

Abstract: The invention concerns an ionizing radiation detector comprising a housing containing: a scintillator material, an avalanche photodiode in contact with the scintillator material via optical coupling, a preamplifier. This detector is compact, portable, and very robust. It detects X-rays or gamma rays with excellent resolution, which can be less than 3% at 662 keV.

Abstract: The invention relates to a crystalline lithium fluoride doped with at least 0.018 mol per kg of a divalent positive ion M present in the fluoride state, in particular of the single-crystal type. The ion may be Mg2+, Zn2+ or Co2+. This fluoride has a high reflectivity and intense radiation that can emanate therefrom may be effectively received by a fast light scintillator, especially of the rare-earth halide type. It is particularly useful as a monochromator for X-ray fluorescence radiation for the purpose of elemental analysis.

Abstract: The invention relates to the handling of a composition comprising a rare-earth halide, especially within the context of the growth of crystals from said composition, said crystals generally being of formula AeLnfX(3f+e) in which Ln represents one or more rare earths, X represents one or more halogen atoms chosen from Cl, Br or I, and A represents one or more alkaline metals such as K, Li, Na, Rb or Cs, e and f representing values such that e, which may be zero, is less than or equal to 2f and f is greater than or equal to 1. It is possible in this way to grow single crystals exhibiting remarkable scintillation properties.

Abstract: The invention relates to an inorganic scintillator material of formula AnLnpX(3p+n) in which Ln represents one or more rare earths, X represents one or more halogen atoms, chosen from F, Cl, Br or I, and A represents one or more alkali metals, such as K, Li, Na, Rb or Cs, n and p representing values such that n, which may be zero, is less than or equal to 2p, and that p is greater than or equal to 1, its content of daughter elements of uranium and thorium being low enough for the activity resulting from the alpha radiation from these elements to be less than 0.7 Bq/cc. This material has a very low nuclear background noise and is particularly suitable as a detector scintillator for coating weight or thickness measurements, in the fields of nuclear medicine, physics, chemistry and oil exploration, and for the detection of dangerous or illicit materials.

Abstract: The invention relates to an inorganic scintillator material of formula Lu(2?y)Y(y?x)CexMzSi(1?v)M?vO5, in which: M represents a divalent alkaline earth metal and M? represents a trivalent metal, (z+v) being greater than or equal to 0.0001 and less than or equal to 0.2, z being greater than or equal to 0 and less than or equal to 0.2; v being greater than or equal to 0 and less than or equal to 0.2, x being greater than or equal to 0.0001 and less than 0.1; and v ranging from (x+z) to 1. In particular, this material may equip scintillation detectors for applications in industry, for the medical field (scanners) and/or for detection in oil drilling, The presence of Ca in the crystal reduces the afterglow, while stopping power for high-energy radiation remains high.

Abstract: The invention relates to a method of preparing a polycrystalline block of a halide of formula AeLnfX(3f+e) in which Ln represents one or more rare earths, X represents one or more halogen atoms selected from the group consisting of Cl, Br and I, and A represents one or more alkali metals selected from the group consisting of K, Li, Na, Rb and Cs, e, which may be zero, being less than or equal to 3f, and f being greater than or equal to 1, having a low water and oxyhalide content, in which the method comprises heating a mixture of, on the one hand, at least one compound having at least one Ln—X bond and, on the other hand, a sufficient amount of NH4X in order to obtain the oxyhalide content, resulting in a molten mass comprising the rare-earth halide, the heating being followed by cooling, and the heating, after having reached 300° C., never going below 200° C. before the molten mass has been obtained.

Abstract: The invention relates to the handling of a composition comprising a rare-earth halide, especially within the context of the growth of crystals from said composition, said crystals generally being of formula AeLnfX(3f+e) in which Ln represents one or more rare earths, X represents one or more halogen atoms chosen from Cl, Br or I, and A represents one or more alkaline metals such as K, Li, Na, Rb or Cs, e and f representing values such that e, which may be zero, is less than or equal to 2f and f is greater than or equal to 1. It is possible in this way to grow single crystals exhibiting remarkable scintillation properties.