Some aspects relate to methods of forming an epitaxial layer. In some examples, the methods include ejecting atoms from a molten metal sputtering material onto a heated crystalline substrate and growing a single epitaxial layer on the substrate from the ejected atoms, where the atoms are ejected with sufficient energy that the grown epitaxial layer has at least a partial rhombohedral lattice, and wherein the crystalline substrate is heated to a temperature of about 600 degrees Celsius or less, or about 500 degrees or less. Other aspects relate to materials, such as a material including a single epitaxial layer on top of a crystalline substrate, the layer including one or more semiconductor materials and having at least a partial rhombohedral lattice, or a substantially rhombohedral lattice.

Various embodiments provide Molten Target Sputtering (MTS) methods and devices. The various embodiments may provide increases in the kinetic energy, increases in the energy latency, and/or increases in the flux density of molecules for better crystal formation at low temperature operation. The various embodiment MTS methods and devices may enable the growth of a single crystal Si.sub.1-xGe.sub.x film on a substrate heated to less than about 500 C. The various embodiment MTS methods and devices may provide increases in the kinetic energy, increases in the energy latency, and/or increases in the flux density of molecules without requiring the addition of extra systems.

Various embodiments provide Molten Target Sputtering (MTS) methods and devices. The various embodiments may provide increases in the kinetic energy, increases in the energy latency, and/or increases in the flux density of molecules for better crystal formation at low temperature operation. The various embodiment MTS methods and devices may enable the growth of a single crystal Si.sub.1-xGe.sub.x film on a substrate heated to less than about 500 C. The various embodiment MTS methods and devices may provide increases in the kinetic energy, increases in the energy latency, and/or increases in the flux density of molecules without requiring the addition of extra systems.

In various embodiments, aluminum nitride single crystals are rapidly diameter-expanded during growth by physical vapor transport. High rates of diameter expansion during growth may be enabled by the use of internal thermal shields and directed plasma-modification of the growth environment to augment radial thermal gradients and increase radial growth rates.

In various embodiments, aluminum nitride single crystals are rapidly diameter-expanded during growth by physical vapor transport. High rates of diameter expansion during growth may be enabled by the use of internal thermal shields and directed plasma-modification of the growth environment to augment radial thermal gradients and increase radial growth rates.

In various embodiments, aluminum nitride single crystals have large crystal augmentation parameters and may therefore be suitable for the fabrication of numerous, large single-crystal aluminum nitride substrates having high crystalline quality. The aluminum nitride single crystals may have large boule masses and volumes.

Some aspects relate to methods of forming an epitaxial layer. In some examples, the methods include ejecting atoms from a molten metal sputtering material onto a heated crystalline substrate and growing a single epitaxial layer on the substrate from the ejected atoms, where the atoms are ejected with sufficient energy that the grown epitaxial layer has at least a partial rhombohedral lattice, and wherein the crystalline substrate is heated to a temperature of about 600 degrees Celsius or less, or about 500 degrees or less. Other aspects relate to materials, such as a material including a single epitaxial layer on top of a crystalline substrate, the layer including one or more semiconductor materials and having at least a partial rhombohedral lattice, or a substantially rhombohedral lattice.

Some aspects relate to methods of forming an epitaxial layer. In some examples, the methods include ejecting atoms from a molten metal sputtering material onto a heated crystalline substrate and growing a single epitaxial layer on the substrate from the ejected atoms, where the atoms are ejected with sufficient energy that the grown epitaxial layer has at least a partial rhombohedral lattice, and wherein the crystalline substrate is heated to a temperature of about 600 degrees Celsius or less, or about 500 degrees or less. Other aspects relate to materials, such as a material including a single epitaxial layer on top of a crystalline substrate, the layer including one or more semiconductor materials and having at least a partial rhombohedral lattice, or a substantially rhombohedral lattice.

Methods and apparatus for improving the loading ratio of a hydrogen gas in a transition metal are disclosed. Blocking desorption sites on the surface of a metallic structure increases the partial hydrogen/deuterium pressure when the absorption and desorption processes reach an equilibrium. The higher the number of desorption sites that are blocked, the higher the equilibrium pressure can be reached for attaining a higher hydrogen loading ratio. Moreover, since hydrogen desorption occurs at grain boundaries, reducing grain boundaries is conducive to reducing the hydrogen desorption rate. Methods and apparatus for increasing grain sizes to reduce grain boundaries are also disclosed.

Methods and apparatus for improving the loading ratio of a hydrogen gas in a transition metal are disclosed. Blocking desorption sites on the surface of a metallic structure increases the partial hydrogen/deuterium pressure when the absorption and desorption processes reach an equilibrium. The higher the number of desorption sites that are blocked, the higher the equilibrium pressure can be reached for attaining a higher hydrogen loading ratio. Moreover, since hydrogen desorption occurs at grain boundaries, reducing grain boundaries is conducive to reducing the hydrogen desorption rate. Methods and apparatus for increasing grain sizes to reduce grain boundaries are also disclosed.