A self-aligned tunable metamaterial is formed as a wire mesh. Self-aligned channel grids are formed in layers in a silicon substrate using deep trench formation and a high-temperature anneal. Vertical wells at the channels may also be etched. This may result in a three-dimensional mesh grid of metal and other material. In another embodiment, metallic beads are deposited at each intersection of the mesh grid, the grid is encased in a rigid medium, and the mesh grid is removed to form an artificial nanocrystal.

A preparation method and application of a Na.sub.3Ba.sub.2(B.sub.3O.sub.6).sub.2F birefringent crystal, the crystal having a chemical formula of Na.sub.3Ba.sub.2(B.sub.3O.sub.6).sub.2F, and belonging to a hexagonal crystal system, the space group being P6.sub.3/m, and the lattice parameters comprising a=7.3490(6) , c=12.6340(2) , V=590.93(12) .sup.3, Z=2; the crystal is used for an infrared/deep ultraviolet waveband, and is an uniaxial negative crystal, n.sub.e<n.sub.o, the transmission range being 175-3,350 nm, the birefringence of 0.090 (3,350 nm)-0.240 (175 nm), and the crystal being grown by employing a melting method or a flux method; the crystal prepared via the method has a short growth cycle, high crystal quality and large crystal size, is easy to grow, cut, polish and store, is stable in the air, and difficult to deliquesce, and can be used for preparation of various polarization beam polarization beam splitter prism and infrared/deep ultraviolet waveband optical communication elements.

A preparation method and application of a Na.sub.3Ba.sub.2(B.sub.3O.sub.6).sub.2F birefringent crystal, the crystal having a chemical formula of Na.sub.3Ba.sub.2(B.sub.3O.sub.6).sub.2F, and belonging to a hexagonal crystal system, the space group being P6.sub.3/m, and the lattice parameters comprising a=7.3490(6) , c=12.6340(2) , V=590.93(12) .sup.3, Z=2; the crystal is used for an infrared/deep ultraviolet waveband, and is an uniaxial negative crystal, n.sub.e<n.sub.o, the transmission range being 175-3,350 nm, the birefringence of 0.090 (3,350 nm)-0.240 (175 nm), and the crystal being grown by employing a melting method or a flux method; the crystal prepared via the method has a short growth cycle, high crystal quality and large crystal size, is easy to grow, cut, polish and store, is stable in the air, and difficult to deliquesce, and can be used for preparation of various polarization beam polarization beam splitter prism and infrared/deep ultraviolet waveband optical communication elements.

Provided is a SiC single crystal that has a large growth thickness and contains no inclusions. A SiC single crystal grown by a solution process, wherein the total length M of the outer peripheral section formed by the {1-100} faces on the {0001} growth surface of the SiC single crystal, and the length P of the outer periphery of the growth surface of the SiC single crystal, satisfy the relationship M/P0.70, and the length in the growth direction of the SiC single crystal is 2 mm or greater.

Provided is a SiC single crystal that has a large growth thickness and contains no inclusions. A SiC single crystal grown by a solution process, wherein the total length M of the outer peripheral section formed by the {1-100} faces on the {0001} growth surface of the SiC single crystal, and the length P of the outer periphery of the growth surface of the SiC single crystal, satisfy the relationship M/P0.70, and the length in the growth direction of the SiC single crystal is 2 mm or greater.

A method of producing a crystal includes a step of preparing a solution containing carbon and a silicon solvent, and a seed crystal of silicon carbide; a step of contacting a lower face of the seed crystal with the solution; a step of raising a temperature of the solution to a first temperature zone; a step of relatively elevating the seed crystal with respect to the solution in a state where a temperature of the solution is being lowered from the first temperature zone to a second temperature zone; a step of raising a temperature of the solution from the second temperature zone to the first temperature zone; and a step of relatively elevating the seed crystal with respect to the solution in a state where a temperature of the solution is being lowered from the first temperature zone to the second temperature zone.

A method of producing a crystal includes a step of preparing a solution containing carbon and a silicon solvent, and a seed crystal of silicon carbide; a step of contacting a lower face of the seed crystal with the solution; a step of raising a temperature of the solution to a first temperature zone; a step of relatively elevating the seed crystal with respect to the solution in a state where a temperature of the solution is being lowered from the first temperature zone to a second temperature zone; a step of raising a temperature of the solution from the second temperature zone to the first temperature zone; and a step of relatively elevating the seed crystal with respect to the solution in a state where a temperature of the solution is being lowered from the first temperature zone to the second temperature zone.

A high-quality SiC single crystal and a method for producing such a SiC single crystal is provided. In the SiC single crystal, the threading dislocation density including screw dislocation, edge dislocation and micropipe defect is reduced. The method for producing the SiC single crystal according to a solution technique involves bringing an SiC seed crystal into contact with an SiC solution having a temperature gradient in which a temperature of the SiC solution is lower towards the surface of the SiC seed crystal. Growing an SiC single crystal includes setting the temperature gradient of the surface region of the SiC solution to 10 C/cm or below, bringing the (1-100) face of the SiC seed crystal into contact with the SiC solution, and growing an SiC single crystal on the (1-100) face of the seed crystal at a ratio (single crystal growth rate/temperature gradient) of less than 2010.sup.4 cm.sup.2/h.Math. C.

A high-quality SiC single crystal and a method for producing such a SiC single crystal is provided. In the SiC single crystal, the threading dislocation density including screw dislocation, edge dislocation and micropipe defect is reduced. The method for producing the SiC single crystal according to a solution technique involves bringing an SiC seed crystal into contact with an SiC solution having a temperature gradient in which a temperature of the SiC solution is lower towards the surface of the SiC seed crystal. Growing an SiC single crystal includes setting the temperature gradient of the surface region of the SiC solution to 10 C/cm or below, bringing the (1-100) face of the SiC seed crystal into contact with the SiC solution, and growing an SiC single crystal on the (1-100) face of the seed crystal at a ratio (single crystal growth rate/temperature gradient) of less than 2010.sup.4 cm.sup.2/h.Math. C.

A p-type SiC single crystal having lower resistivity than the prior art is provided. This is achieved by a method for producing a SiC single crystal in which a SiC seed crystal substrate is contacted with a SiC solution having a temperature gradient such that the temperature decreases from the interior toward the surface, to grow a SiC single crystal, the method comprising: using as the SiC solution a SiC solution containing Si, Cr and Al, wherein the Al content is 3 at % or greater based on the total of Si, Cr and Al; and contacting a (0001) face of the SiC seed crystal substrate with the SiC solution to grow a SiC single crystal from the (0001) face.