A device configured to convert or amplify a particle, the conversion or amplification being reliant on the impact of a particle on a surface of the device causing emission of one or more secondary electrons from the same surface. The device includes a carbon-based layer capable of secondary electron emission upon impact of a particle. The surface may be used to convert, for example, an ion into an electron signal, or an electron signal into an amplified electron signal, such as in conversion or amplification dynodes.

[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 provided a piezoelectric substrate including a lithium-containing metal compound crystal such as a lithium tantalate (LT) crystal, wherein potassium is contained in the substrate and the distribution of potassium is approximately uniform as observed in the direction of the thickness of the substrate. There is also provided a piezoelectric substrate, wherein a peak coming from LiO lattice vibration and appearing around 380 cm.sup.1 is shifted to a high wave number side compared with that in an untreated piezoelectric substrate having a conductivity of 110.sup.15 S/cm or less in Raman spectra measured from the cross section direction.

Devices containing novel conductive monocrystalline magnesium oxides are provided. The devices may be an energy storage device, a wide band gap semiconductor, or a gate dielectric. The conductive monocrystalline magnesium oxides have a purity of at least 98% and have an imaginary contribution to the dielectric permittivity () of at most 0.03 at a frequency of 0.031 Hz or have a conductivity of at least 10.sup.8.4 S*m.sup.1 at a frequency of 0.031 Hz. Certain conductive monocrystalline magnesium oxides have a positive charge density.

A substrate 10 comprises: a first layer L1 containing crystalline aluminum nitride; a second layer L2 containing crystalline -alumina; and an intermediate layer Lm sandwiched between the first layer L1 and the second layer L2 and containing aluminum, nitrogen, and oxygen, and the content of nitrogen in the intermediate layer Lm decreases in a direction Z from the first layer L1 toward the second layer L2, and the content of oxygen in the intermediate layer Lm increases in the direction Z from the first layer L1 toward the second layer L2.

Systems and methods for the rapid growth of Group III metal nitrides using plasma assisted molecular beam epitaxy. The disclosure includes higher pressure and flow rates of nitrogen in the plasma, and the application of mixtures of nitrogen and an inert gas. Growth rates exceeding 8 m/hour can be achieved.

Systems and methods for the rapid growth of Group III metal nitrides using plasma assisted molecular beam epitaxy. The disclosure includes higher pressure and flow rates of nitrogen in the plasma, and the application of mixtures of nitrogen and an inert gas. Growth rates exceeding 8 m/hour can be achieved.

Using processes disclosed herein, materials and structures are created and used. For example, processes can include melting boron nitride or amorphous carbon into an undercooled state followed by quenching. Exemplary new materials disclosed herein can be ferromagnetic and/or harder than diamond. Materials disclosed herein may include dopants in concentrations exceeding thermodynamic solubility limits. A novel phase of solid carbon has structure different than diamond and graphite.

Using processes disclosed herein, materials and structures are created and used. For example, processes can include melting boron nitride or amorphous carbon into an undercooled state followed by quenching. Exemplary new materials disclosed herein can be ferromagnetic and/or harder than diamond. Materials disclosed herein may include dopants in concentrations exceeding thermodynamic solubility limits. A novel phase of solid carbon has structure different than diamond and graphite.

Using processes disclosed herein, materials and structures are created and used. For example, processes can include melting boron nitride or amorphous carbon into an undercooled state followed by quenching. Exemplary new materials disclosed herein can be ferromagnetic and/or harder than diamond. Materials disclosed herein may include dopants in concentrations exceeding thermodynamic solubility limits. A novel phase of solid carbon has structure different than diamond and graphite.