A composite has a solid-state structure, silicate, lithium ions, and at least one paramagnetic or diamagnetic element, which is different from lithium silicon, and oxygen. The solid-state structure has two areas in which the solid-state structure forms an identical crystal orientation. The areas are arranged at a distance of at least one millimeter from each other. A method has a quenching step in which a solid-state structure of a composite is produced, which differs from an ambient temperature solid-state structure. The composite produced by the method has silicate, lithium ions, and an element that is different from lithium, silicon, and oxygen. The method produces at least one gram of the phase pure composite in the quenching step.

Silicon carbide (SiC) wafers and related methods are disclosed that include large diameter SiC wafers with wafer shape characteristics suitable for semiconductor manufacturing. Large diameter SiC wafers are disclosed that have reduced deformation related to stress and strain effects associated with forming such SiC wafers. As described herein, wafer shape and flatness characteristics may be improved by reducing crystallographic stress profiles during growth of SiC crystal boules or ingots. Wafer shape and flatness characteristics may also be improved after individual SiC wafers have been separated from corresponding SiC crystal boules. In this regard, SiC wafers and related methods are disclosed that include large diameter SiC wafers with suitable crystal quality and wafer shape characteristics including low values for wafer bow, warp, and thickness variation.

[Object] It is an object of the present invention to provide a lithium tantalate single crystal substrate which undergoes only small warpage, is free from cracks and scratches, has better temperature non-dependence characteristics and a larger electromechanical coupling coefficient than a conventional Y-cut LiTaO.sub.3 substrate. [Means to solve the Problems] The lithium tantalate single crystal substrate of the present invention is a rotated Y-cut LiTaO.sub.3 single crystal substrate having a crystal orientation of 36° Y-49° Y cut characterized in that: the substrate is diffused with Li from its surface into its depth such that it has a Li concentration profile showing a difference in the Li concentration between the substrate surface and the depth of the substrate; and the substrate is treated with single polarization treatment so that the Li concentration is substantially uniform from the substrate surface to a depth which is equivalent to 5-15 times the wavelength of either a surface acoustic wave or a leaky surface acoustic wave propagating in the LiTaO.sub.3 substrate surface.

[Object] It is an object of the present invention to provide a lithium tantalate single crystal substrate which undergoes only small warpage, is free from cracks and scratches, has better temperature non-dependence characteristics and a larger electromechanical coupling coefficient than a conventional Y-cut LiTaO.sub.3 substrate. [Means to solve the Problems] The lithium tantalate single crystal substrate of the present invention is a rotated Y-cut LiTaO.sub.3 single crystal substrate having a crystal orientation of 36° Y-49° Y cut characterized in that: the substrate is diffused with Li from its surface into its depth such that it has a Li concentration profile showing a difference in the Li concentration between the substrate surface and the depth of the substrate; and the substrate is treated with single polarization treatment so that the Li concentration is substantially uniform from the substrate surface to a depth which is equivalent to 5-15 times the wavelength of either a surface acoustic wave or a leaky surface acoustic wave propagating in the LiTaO.sub.3 substrate surface.

There is described a single crystal CVD diamond material comprising three orthogonal dimensions of at least 2 mm; one or more regions of low optical birefringence, indicative of low strain, such that in a sample of the single crystal CVD diamond material having a thickness in a range 0.5 mm to 1.0 mm and an area of greater than 1.3 mm×1.3 mm and measured using a pixel size of area in a range 1×1 μm.sup.2 to 20×20 μm.sup.2, a maximum value of Δn.sub.[average] does not exceed 1.5×10.sup.−4 for the one or more regions of low optical birefringence, where Δn.sub.[average] is an average value of a difference between refractive index for light polarised parallel to slow and fast axes averaged over the sample thickness; one or more regions of high optical birefringence, indicative of high strain, such that in said sample of the single crystal CVD diamond material and measured using said pixel size, Δn.sub.[average] is greater than 1.5×10.sup.−4 and less than 3×10.sup.−3; and is wherein every 1.3 mm×1.3 mm area of the sample of the single crystal CVD diamond material comprises at least one of said regions of high optical birefringence. There is also described a method of making the CVD diamond material.

There is described a single crystal CVD diamond material comprising three orthogonal dimensions of at least 2 mm; one or more regions of low optical birefringence, indicative of low strain, such that in a sample of the single crystal CVD diamond material having a thickness in a range 0.5 mm to 1.0 mm and an area of greater than 1.3 mm×1.3 mm and measured using a pixel size of area in a range 1×1 μm.sup.2 to 20×20 μm.sup.2, a maximum value of Δn.sub.[average] does not exceed 1.5×10.sup.−4 for the one or more regions of low optical birefringence, where Δn.sub.[average] is an average value of a difference between refractive index for light polarised parallel to slow and fast axes averaged over the sample thickness; one or more regions of high optical birefringence, indicative of high strain, such that in said sample of the single crystal CVD diamond material and measured using said pixel size, Δn.sub.[average] is greater than 1.5×10.sup.−4 and less than 3×10.sup.−3; and is wherein every 1.3 mm×1.3 mm area of the sample of the single crystal CVD diamond material comprises at least one of said regions of high optical birefringence. There is also described a method of making the CVD diamond material.

A treatment method of a sapphire material, said method comprising bombardment of a surface of the sapphire material, said surface facing a medium different from the sapphire material, by a single- and/or multi-charged gas ion beam so as to produce an ion implanted layer in the sapphire material, wherein the ions are selected from ions of the elements from the list consisting of helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), boron (B), carbon (C), nitrogen (N), oxygen (O), fluorine (F), silicon (Si), phosphorus (P) and sulphur (S). Use of said method to obtain a capacitive touch panel having a high transmission in the visible range.

A treatment method of a sapphire material, said method comprising bombardment of a surface of the sapphire material, said surface facing a medium different from the sapphire material, by a single- and/or multi-charged gas ion beam so as to produce an ion implanted layer in the sapphire material, wherein the ions are selected from ions of the elements from the list consisting of helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), boron (B), carbon (C), nitrogen (N), oxygen (O), fluorine (F), silicon (Si), phosphorus (P) and sulphur (S). Use of said method to obtain a capacitive touch panel having a high transmission in the visible range.

Provided are a diamond composite body capable of shortening a separation time for separating a substrate and a diamond layer, the substrate, and a method for manufacturing a diamond, as well as a diamond obtained from the diamond composite body and a tool including the diamond. The diamond composite body includes a substrate including a diamond seed crystal and having grooves in a main surface, a diamond layer formed on the main surface of the substrate, and a non-diamond layer formed on a substrate side at a constant depth from an interface between the substrate and the diamond layer.

Provided are a diamond composite body capable of shortening a separation time for separating a substrate and a diamond layer, the substrate, and a method for manufacturing a diamond, as well as a diamond obtained from the diamond composite body and a tool including the diamond. The diamond composite body includes a substrate including a diamond seed crystal and having grooves in a main surface, a diamond layer formed on the main surface of the substrate, and a non-diamond layer formed on a substrate side at a constant depth from an interface between the substrate and the diamond layer.