Methods, apparatus, and systems for fabricating diffractive structures on gemstones for high optical performance are provided. In one aspect, a method includes obtaining a plurality of gemstone characteristics of a gemstone, determining that the gemstone exhibits each of the plurality of gemstone characteristics within a respective predetermined range, identifying a diffractive structure setting associated with a combination of the respective predetermined ranges for the plurality of gemstone characteristics, and fabricating diffractive structures on the gemstone according to the diffractive structure setting.

Methods, apparatus, and systems for fabricating diffractive structures on gemstones for high optical performance are provided. In one aspect, a method includes obtaining a plurality of gemstone characteristics of a gemstone, determining that the gemstone exhibits each of the plurality of gemstone characteristics within a respective predetermined range, identifying a diffractive structure setting associated with a combination of the respective predetermined ranges for the plurality of gemstone characteristics, and fabricating diffractive structures on the gemstone according to the diffractive structure setting.

A structure includes a semiconductor substrate, and a polycrystalline resistor region over the semiconductor substrate. The polycrystalline resistor region includes a semiconductor material in a polycrystalline morphology. A dopant-including polycrystalline region is between the polycrystalline resistor region and the semiconductor substrate.

The present application provides a lithium niobate having a p-type nanowire region or an n-type nanowire region and a method for preparing the same. The method includes heating and then cooling a multi-domain lithium niobate crystal to confine hydrogen ions of the multi-domain lithium niobate crystal in domain wall regions; and poling the multi-domain lithium niobate crystal that has been heated by applying a voltage, to reverse a direction of polarization of one or more domains of the multi-domain lithium niobate crystal. The lithium niobate includes a lithium niobate crystal and a p-type nanowire region or an n-type nanowire region located in the lithium niobate crystal and adjacent to a surface of the lithium niobate crystal. The present application also provides a method for converting the charge carrier type of the lithium niobate nanowire region.

The present application provides a lithium niobate having a p-type nanowire region or an n-type nanowire region and a method for preparing the same. The method includes heating and then cooling a multi-domain lithium niobate crystal to confine hydrogen ions of the multi-domain lithium niobate crystal in domain wall regions; and poling the multi-domain lithium niobate crystal that has been heated by applying a voltage, to reverse a direction of polarization of one or more domains of the multi-domain lithium niobate crystal. The lithium niobate includes a lithium niobate crystal and a p-type nanowire region or an n-type nanowire region located in the lithium niobate crystal and adjacent to a surface of the lithium niobate crystal. The present application also provides a method for converting the charge carrier type of the lithium niobate nanowire region.

Provided is a manufacturing method with which it is possible to convert a mayenite-type compound to an electride, wherein a reducing agent is not required, reaction conditions include a temperature that is lower than that in the related art, and the reaction is performed more quickly in a simple manner, and, additionally, by requiring a lower amount of energy. Provided is a method for manufacturing an electride of mayenite-type compounds, the method being characterized in that a mayenite-type compound is converted to an electride by making a current directly flow through the mayenite-type compound by applying a voltage to the mayenite-type compound in a heating state.

Provided is a manufacturing method with which it is possible to convert a mayenite-type compound to an electride, wherein a reducing agent is not required, reaction conditions include a temperature that is lower than that in the related art, and the reaction is performed more quickly in a simple manner, and, additionally, by requiring a lower amount of energy. Provided is a method for manufacturing an electride of mayenite-type compounds, the method being characterized in that a mayenite-type compound is converted to an electride by making a current directly flow through the mayenite-type compound by applying a voltage to the mayenite-type compound in a heating state.

A solid ion conductive material can include a complex metal halide. The complex metal halide can include at least one alkali metal element. In an embodiment, the solid ion conductive material including the complex metal halide can be a single crystal. In another embodiment, the ion conductive material including the complex metal halide can be a crystalline material having a particular crystallographic orientation. A solid electrolyte can include the ion conductive material including the complex metal halide.

The invention relates to marks used for marking gemstones, including diamonds or brilliants, and carrying information for various purposes, for example, identification codes. In particular, the marks are invisible to the naked eye, using magnifying glasses and various types of microscopes. The marks are located inside the volume of diamonds or brilliants without affecting their characteristics, resulting in damage to the quality of diamonds or brilliants. An optically permeable mark located inside the diamond or brilliant volume is disclosed. The mark contains predefined encoded information and consists of a given set of optically permeable elements of micron or submicron size, which represent areas of increased concentration of atomic defects in the diamond or brilliant crystal lattice. The atomic defects in the diamond or brilliant crystal lattice are vacancies and interstitials, wherein said information is encoded in at least two areas of increased concentration of said atomic defects.

Provided is a manufacturing method with which it is possible to convert a mayenite-type compound to an electride, wherein a reducing agent is not required, reaction conditions include a temperature that is lower than that in the related art, and the reaction is performed more quickly in a simple manner, and, additionally, by requiring a lower amount of energy. Provided is a method for manufacturing an electride of mayenite-type compounds, the method being characterized in that a mayenite-type compound is converted to an electride by making a current directly flow through the mayenite-type compound by applying a voltage to the mayenite-type compound in a heating state.