1. An article comprising:
a substrate;
an interlayer comprising aluminum nitride, gallium nitride, boron nitride, indium nitride or a solid solution of aluminum nitride, gallium nitride, boron nitride andor indium nitride; the interlayer being directly disposed upon the substrate and in contact with the substrate; where the interlayer comprises a columnar film andor nanorods andor nanotubes; and
a group-III nitride layer disposed upon the interlayer; where the group-III nitride layer completely covers a surface of the interlayer that is opposed to a surface in contact with the substrate; the group-III nitride layer being free from cracks, wherein the interlayer is in direct contact with the group-III nitride layer.
2. The article of claim 1, where the substrate comprises silicon, SiC, sapphire (c-, a-, r- or m-oriented; on axis or of-cut), LiAlO2, LiGaO2, gallium arsenide, glass, alumina, titania, zirconia, germanium, a combination of germanium and silicon, aluminum nitride, indium nitride, boron nitride, gallium nitride or a solid solution of aluminum nitride, indium nitride, boron nitride andor gallium nitride, quartz and glass.
3. The article of claim 1, where the interlayer comprising a solid solution of aluminum nitride, gallium nitride, boron nitride andor indium nitride comprises aluminum indium nitride, indium boron nitride, aluminum boron nitride, gallium boron nitride, aluminum gallium nitride, gallium indium nitride, aluminum indium gallium nitride, indium gallium boron nitride, aluminum gallium boron nitride, aluminum gallium boron nitride, indium aluminum boron nitride, or aluminum gallium indium boron nitride.
4. The article of claim 1, where the interlayer comprises a chemical composition represented by the Equation (I):
AxByCzN\u2003\u2003(I)
where x+y+z=1 and x is an amount of about 0 to about 1, y is an amount of about 0 to about 1 and z is an amount of about 0 to about 1; where A, B and C can be the same or different and can be selected from amongst indium, aluminum, boron or gallium and where N is nitrogen.
5. The article of claim 1, where the columnar film comprises columns having an average column diameter of about 0.1 micrometer to about 1 micrometer.
6. The article of claim 1, where the nanorods are aligned to be substantially perpendicular to the substrate.
7. The article of claim 1, where the nanorods are randomly aligned.
8. The article of claim 1, where the substrate comprises silica, alumina or gallium nitride, the interlayer comprises indium nitride and the group-III layer comprises gallium nitride.
9. The article of claim 1, where the substrate further comprises a buffer layer.
10. The article of claim 9, where the buffer layer comprises nuclei that nucleate the nanorods.
11. The article of claim 10, where the nuclei comprise a native group-III nitride or an alloy of a native group-III nitride.
12. A method comprising:
disposing on a substrate an interlayer comprising interlayer comprising aluminum nitride, gallium nitride, boron nitride, indium nitride or a solid solution of aluminum nitride, gallium nitride, boron nitride andor indium nitride; the interlayer being directly disposed upon the substrate and in contact with the substrate; where the interlayer comprises a columnar film andor nanorods andor nanotubes; and
disposing on the interlayer a group-III nitride layer; where the group-III nitride layer is free from cracks and wherein the interlayer is in direct contact with the group-III nitride layer.
13. The method of claim 12, further comprising disposing a buffer layer on the substrate, the buffer layer comprising a native group-III nitride or an alloy of a native group-III nitride.
14. The method of claim 12, where the interlayer is disposed on the substrate at a temperature of about 400 to about 800\xb0 C.
15. The method of claim 12, where the interlayer is disposed on the substrate at a temperature of about 575 to about 700\xb0 C.
16. The method of claim 12, where the interlayer is disposed on the substrate by reacting a first reactive precursor with a halogen containing compound and a nitrogen containing compound.
17. The method of claim 16, where the first reactive precursor is selected from the group consisting of boron tribromide, trimethylaluminum, ethyldimethylindium, boron trichloride, trimethylgallium, triethylgallium, trimethylindium, triethylindium, and a combination comprising at least one of the foregoing reactive precursors.
18. The method of claim 16, wherein a ratio of the halogen containing compound to the first reactive precursor is about 1 to about 6.
19. The method of claim 16, wherein a ratio of the halogen containing compound to the first reactive precursor is about 2 to about 4.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A process for the dehydration of gases, comprising:
a. absorbing water vapor by means of a hygroscopic liquid consisting essentially of one or more C2-C8 glycols and an additive capable of forming a minimum type azeotrope with water, selected from the group consisting of:
aliphatic alcohols with a number of carbon atoms ranging from 5 to 8, or mixtures thereof; and
cumene (isopropylbenzene)
\u2003with a glycolwater vapor molar ratio of from 6.5 to 65,
\u2003wherein the additive is used in concentrations of from 2 to 20% by weight, with respect to the glycol;
b. distilling the glycolwateradditive mixture to obtain a top product consisting essentially of the azeotropic mixture (additive+water) and a bottom product consisting essentially of glycol and additive;
c. recycling the distillation bottom product (hygroscopic absorption liquid) to the absorption stage; and
d. separating, in an at least two phase separator, the distillation top product which separates into one phase consisting essentially of the additive, to be recycled to distillation, and one phase consisting essentially of water, to be discharged outside the plant.
2. The process according to claim 1, wherein the additive is selected from cumene or an aliphatic alcohol with a number of carbon atoms of 6 or 7, or a mixture thereof.
3. The process according to claim 2, wherein the additive is 1-hexanol or 1-heptanol or a mixture thereof.
4. The process according to claim 1, wherein the absorption takes place at a temperature of from 10 to 50\xb0 C.
5. The process according to claim 1, wherein the gas is natural gas.
6. The process according to claim 1, wherein the additive is cumene.
7. The process according to claim 1, wherein additive is an aliphatic alcohol having 6 or 7 carbon atoms.
8. The process according to claim 1, wherein the distilling the glycolwateradditive mixture is conducted at a temperature of 150 to 225\xb0 C.
9. A process for the dehydration of gases, comprising:
a. absorbing water vapor from a gas with a hygroscopic liquid consisting essentially of (1) one or more C2-C8 glycols and (2) an additive capable of forming a minimum type azeotrope with water and selected from the group consisting of:
aliphatic alcohols with a number of carbon atoms ranging from 5 to 8, or mixtures thereof and
cumene,
\u2003with a glycolwater vapor molar ratio of from 6.5 to 65,
\u2003wherein the additive is used in an amount of from 2 to 20% by weight, with respect to the glycol;
b. distilling the glycolwateradditive mixture to obtain a top product consisting essentially of the additive and water as an azeotropic mixture and a bottom product consisting essentially of glycol and additive;
c. recycling the bottom product to (a); and
d. separating, in an at least two phase separator, the top product which separates into one phase consisting essentially of the additive and one phase consisting essentially of water.
10. The process according to claim 9, wherein the gas is natural gas.
11. The process according to claim 9, wherein the additive is an aliphatic alcohol having 6 or 7 carbon atoms.
12. The process according to claim 9, wherein the additive is 1-hexanol or 1-heptanol or a mixture thereof.
13. The process according to claim 9, wherein the additive is cumene.
14. The process according to claim 9, wherein the absorption is conducted at a temperature of from 10 to 50\xb0 C.
15. The process according to claim 9, wherein the distilling the glycolwateradditive mixture is conducted at a temperature of 150 to 225\xb0 C.
16. The process according to claim 9, further comprising recycling the one phase consisting essentially of the additive to the distillation.
17. The process according to claim 9, further comprising discharging the one phase consisting essentially of water.