Abstract: A scintillation compound can include a rare earth element that is in a divalent (RE2+) or a tetravalent state (RE4+). The scintillation compound can include another element to allow for better change balance. The other element may be a principal constituent of the scintillation compound or may be a dopant or a co-dopant. In an embodiment, a metal element in a trivalent state (M3+) may be replaced by RE4+ and a metal element in a divalent state (M2+). In another embodiment, M3+ may be replaced by RE2+ and M4+. In a further embodiment, M2+ may be replaced by a RE3+ and a metal element in a monovalent state (M1+). The metal element used for electronic charge balance may have a single valance state, rather than a plurality of valence states, to help reduce the likelihood that the valance state would change during formation of the scintillation compound.

Abstract: A scintillation crystal can include a rare earth silicate, an activator, and a Group 2 co-dopant. In an embodiment, the Group 2 co-dopant concentration may not exceed 200 ppm atomic in the crystal or 0.25 at % in the melt before the crystal is formed. The ratio of the Group 2 concentration/activator atomic concentration can be in a range of 0.4 to 2.5. In another embodiment, the scintillation crystal may have a decay time no greater than 40 ns, and in another embodiment, have the same or higher light output than another crystal having the same composition except without the Group 2 co-dopant. In a further embodiment, a boule can be grown to a diameter of at least 75 mm and have no spiral or very low spiral and no cracks. The scintillation crystal can be used in a radiation detection apparatus and be coupled to a photosensor.

Abstract: A scintillation crystal can include a rare earth silicate, an activator, and a Group 2 co-dopant. In an embodiment, the Group 2 co-dopant concentration may not exceed 200 ppm atomic in the crystal or 0.25 at in the melt before the crystal is formed. The ratio of the Group 2 concentration/activator atomic concentration can be in a range of 0.4 to 2.5. In another embodiment, the scintillation crystal may have a decay time no greater than 40 ns, and in another embodiment, have the same or higher light output than another crystal having the same composition except without the Group 2 co-dopant. In a further embodiment, a boule can be grown to a diameter of at least 75 mm and have no spiral or very low spiral and no cracks. The scintillation crystal can be used in a radiation detection apparatus and be coupled to a photosensor.

Abstract: A scintillation crystal can include a rare earth silicate, an activator, and a Group 2 co-dopant. In an embodiment, the Group 2 co-dopant concentration may not exceed 200 ppm atomic in the crystal or 0.25 at % in the melt before the crystal is formed. The ratio of the Group 2 concentration/activator atomic concentration can be in a range of 0.4 to 2.5. In another embodiment, the scintillation crystal may have a decay time no greater than 40 ns, and in another embodiment, have the same or higher light output than another crystal having the same composition except without the Group 2 co-dopant. In a further embodiment, a boule can be grown to a diameter of at least 75 mm and have no spiral or very low spiral and no cracks. The scintillation crystal can be used in a radiation detection apparatus and be coupled to a photosensor.

Abstract: A scintillator can include a monocrystalline compound having a general formula Na(1-y)LiyX, where 0<y<1 and X is at least one halogen or any combination of halogens. In an embodiment, the scintillator can have a Pulse Shape Discrimination Figure of Merit of at least 1 at a temperature of 25° C., at a temperature of 150° C., or both.

Abstract: High quality free standing GaN is obtained using a new modification of the Epitaxial Lateral Overgrowth technology in which 3D islands or features are created only by tuning the growth parameters. Smoothing these islands (2D growth) is achieved thereafter by setting growth conditions producing enhanced lateral growth. The repetition of 3D-2D growth results in multiple bending of the threading dislocations thus producing thick layers or free standing GaN with threading dislocation density below 106 cm?2.

Abstract: The invention relates to a method for manufacturing a single crystal of nitride by epitaxial growth on a support (100) comprising a growth face (105), the method comprising the steps of formation of a sacrificial bed (101) on the support (100), formation of pillars (102) on said sacrificial bed, said pillars being made of a material compatible with GaN epitaxial growth, growth of a nitride crystal layer (103) on the pillars, under growing conditions such that the nitride crystal layer does not extend down to the support in holes (107) formed between the pillars, and removing the nitride crystal layer from the support.

Abstract: The invention relates to a tetragonal single crystal (1, 11) of composition: Z(H,D)2MO4 where Z is an element or a group of elements, or a mixture of elements and/or of groups of elements chosen from the group K, N(H,D)4, Rb, Ce where M is an element chosen from the group P, As and where (H,D) is hydrogen and/or deuterium comprising an approximately parallelepipedal region of large dimensions, especially one in which the length of each of the edges of the faces, AC1, AC2, AC3, is greater than or equal to 200 mm, in particular greater than or equal to 500 mm, which crystal is obtained by crystal growth from solution, from an approximately parallelepipedal single-crystal seed (2, 22) whose edges of the faces have lengths of AG1, AG2, AG3.

Abstract: A monoclinic single crystal with a lutetium pyrosilicate structure is described. The crystal is formed by crystallization from a congruent molten composition of LU2(1-x)M2xSi2O7 where LU is lutetium or a lutetium-based alloy which also includes one or more of scandium, ytterbium, indium, lanthanum, and gadolinium; where M is cerium or cerium partially substituted with one or more of the elements of the lanthanide family excluding lutetium; and where x is defined by the limiting level of LU substitution with M in a monoclinic crystal of the lutetium pyrosilicate structure. The LU alloy should contain greater than about 75 weight percent lutetium. The crystals exhibit excellent and reproducible scintillation response to gamma radiation.