The presently disclosed and/or claimed inventive concept(s) relates generally to hexagonal osmium boride, OsB.sub.2, and methods of producing the same. In one non-limiting embodiment, hexagonal OsB.sub.2 is produced by mechanochemical synthesis of osmium and boron in a high energy ball mill.

A method of synthesizing uranium dioxide crystals. The method of synthesizing includes combining a uranium-based feedstock with a mineralizer solution. The uranium-based feedstock is selected from uranium dioxide, uranium tetrafluoride, uranium tetrachloride, triuranium octoxide, and uranium trioxide. The feedstock and mineralizer solution are pressurized, and then a thermal gradient is applied thereto such that a first portion of the feedstock and the mineralizer solution is heated to a temperature that is greater than a temperature of a second portion of the feedstock and the mineralizer solution. The uranium nutrient enters the mineralizer solution from the feedstock in the first portion and uranium nutrient precipitates to spontaneously form crystals in the second portion.

According to the embodiment, a radiation detector includes a photoelectric conversion substrate converting light to an electrical signal and a scintillator layer being in contact with the photoelectric conversion substrate and converting externally incident radiation to light. The scintillator layer is made of a phosphor containing Tl as an activator in CsI, which is a halide. A concentration of the activator in the phosphor is 1.6 mass %0.4 mass %, and a concentration distribution of the activator in an in-plane direction and a film thickness direction is within 15%.

According to the embodiment, a radiation detector includes a photoelectric conversion substrate converting light to an electrical signal and a scintillator layer being in contact with the photoelectric conversion substrate and converting externally incident radiation to light. The scintillator layer is made of a phosphor containing Tl as an activator in CsI, which is a halide. A concentration of the activator in the phosphor is 1.6 mass %0.4 mass %, and a concentration distribution of the activator in an in-plane direction and a film thickness direction is within 15%.

A method for growing a periodically-poled nonlinear crystal may include placing a seed crystal into a melt to form a seed crystal melt mixture, where the seed crystal may include at least one of strontium tetraborate (SBO) or lithium triborate (LBO), and where the melt includes at least one of a mixture of Sr, B, and O or a mixture of Li, B, and O. The method may further include heating the seed crystal melt mixture to a predetermined temperature until the periodically-poled nonlinear crystal forms.

A method for growing a periodically-poled nonlinear crystal may include placing a seed crystal into a melt to form a seed crystal melt mixture, where the seed crystal may include at least one of strontium tetraborate (SBO) or lithium triborate (LBO), and where the melt includes at least one of a mixture of Sr, B, and O or a mixture of Li, B, and O. The method may further include heating the seed crystal melt mixture to a predetermined temperature until the periodically-poled nonlinear crystal forms.

A solution deposition method includes: applying a liquid precursor solution to a substrate, the precursor solution including an oxide of a first metal, a hydroxide of the first metal, or a combination thereof, dissolved in an aqueous ammonia solution; evaporating the precursor solution to directly form a solid seed layer on the substrate, the seed layer including an oxide of the first metal, a hydroxide of the first metal, or a combination thereof, the seed layer being substantially free of organic compounds; and growing a bulk layer on the substrate, using the seed layer as a growth site or a nucleation site.

A solution deposition method includes: applying a liquid precursor solution to a substrate, the precursor solution including an oxide of a first metal, a hydroxide of the first metal, or a combination thereof, dissolved in an aqueous ammonia solution; evaporating the precursor solution to directly form a solid seed layer on the substrate, the seed layer including an oxide of the first metal, a hydroxide of the first metal, or a combination thereof, the seed layer being substantially free of organic compounds; and growing a bulk layer on the substrate, using the seed layer as a growth site or a nucleation site.

The present invention relates to a barium tetraborate compound and a barium tetraborate non-linear optical crystal, and a preparation method and use thereof, wherein the chemical formulae of the barium tetraborate compound and the non-linear optical crystal thereof are both BaB.sub.4O.sub.7, with a molecular weight of 292.58; the barium tetraborate non-linear optical crystal has a non-centrosymmetric structure, which belongs to a hexagonal system, and has a space group P6.sub.5 and lattice parameters of a=6.7233(6) , c=18.776(4) , V=735.01(17) .sup.3, and Z=6, wherein the powder frequency-doubled effect thereof is two times that of KDP (KH.sub.2PO.sub.4), and the ultraviolet cut-off edge is lower than 170 nm. The barium tetraborate compound is synthesized by a solid-phase reaction method; the barium tetraborate non-linear optical crystal is grown by a high-temperature molten solution method; and the crystal has a moderate mechanical hardness, is easy to cut, polish and store, and is widely applicable in the non-linear optics of a double-frequency doubling generator, an upper frequency converter, a lower frequency converter or an optical parameter oscillator etc.

The presently disclosed and/or claimed inventive concept(s) relates generally to hexagonal osmium boride, OsB.sub.2, and methods of producing the same. In one non-limiting embodiment, hexagonal OsB.sub.2 is produced by mechanochemical synthesis of osmium and boron in a high energy ball mill.