JP2005349515A - Aluminum nitride nano tube whose outer wall and inner wall are covered with carbon film and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aluminum nitride nano tube whose outer wall and inner wall are covered with a carbon film and a manufacturing method thereof, by growth of a carbon film on the outer wall and the inner wall of the aluminum nitride nano tube, which is expected for application to the field of optoelectronics or electric field discharge material. <P>SOLUTION: A mixture of alumina powder and carbon nano-tube is heated for 0.4 to 1 hour to 1450 to 1600°C in an atmosphere of inert gas, and after that, inert bas is switched to ammonia gas to continuously heat the same for 0.5 to 1.2 hour to 1300 to 1600°C. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The invention of this application relates to an aluminum nitride nanotube whose outer wall and inner wall are covered with a carbon film, and a method for producing the same.

Methods for producing one-dimensional aluminum nitride nanowires (for example, see Non-Patent Documents 1 to 3) and aluminum nitride nanotubes (for example, Non-Patent Documents 4 and 5) are known so far. Among these, aluminum nitride nanotubes are manufactured by an arc discharge method using aluminum as a target material or a method of reacting aluminum powder with ammonia.
Y. Zhang et al., Chemistry of Materials (Chem. Mater.), 2001, Vol. 13, p. 3899 C.Xu, Phys. Stat. Sol. A, 2003, Vol. 198, p. 329 XPHao et al., Journal of Crystal Growth (J.Cryst.Growth), 2002, Vol.242, p. 229 Outside VNTondare, Applied Physics Letters (Appl. Phys. Lett.), 2002, 80, p. 4813 Q. Wu et al., Journal of American Chemical Society (J. Am. Chem. Soc.), 2003, Vol. 125, p. 10176

  The invention of this application is a new, carbon film grown on the outer and inner walls of aluminum nitride nanotubes, and is expected to be applied to fields such as optoelectronics and field emission materials. The outer and inner walls are covered with a carbon film. It is a problem to be solved to provide an aluminum nitride nanotube and a method for producing the same.

  In order to solve the above problems, the invention of this application is as follows. First, both the outer wall and the inner wall of the aluminum nitride nanotube are covered with a carbon film, the outer diameter is 45 to 50 nanometers, and the thickness of the carbon film is Provided is an aluminum nitride nanotube having an outer wall and an inner wall covered with a carbon film, wherein the outer wall and the inner wall have a thickness of 2 to 3 nm and a wall thickness of 10 to 15 nm.

  The invention of this application is characterized in that, secondly, an outer wall and an inner wall are characterized in that a mixture of alumina powder and carbon nanotubes is heated in an inert gas stream, and then the inert gas is switched to ammonia gas and subsequently heated. A method for producing an aluminum nitride nanotube covered with a carbon film is provided.

  Thirdly, in the method of manufacturing an aluminum nitride nanotube in which the second outer wall and the inner wall are covered with a carbon film, the weight ratio of the alumina powder to the carbon nanotube is 4: 1 to 3: 1. Provided is a method for producing an aluminum nitride nanotube in which an outer wall and an inner wall which are ranges are covered with a carbon film.

The invention of this application is, fourthly, in the method for producing an aluminum nitride nanotube in which the second or third outer wall and the inner wall are covered with a carbon film, in an inert gas stream, at 1450 to 1600 ° C.
The manufacturing method of the aluminum nitride nanotube heated at the temperature of the range is provided.

The fifth aspect of the invention of this application is that, in the fourth method for producing an aluminum nitride nanotube in which the outer wall and the inner wall are covered with a carbon film, the aluminum nitride nanotube is heated in an inert gas stream for 0.4 to 1 hour. Provide a method.

  The invention of this application is sixthly, in the method for producing an aluminum nitride nanotube in which the outer wall and the inner wall of any one of the second to fifth are covered with a carbon film, in an ammonia gas stream, the temperature is 1300 to 1600 ° C. Provided is a method for producing aluminum nitride nanotubes that is heated at a range of temperatures.

  Seventhly, the invention of this application is the method for producing aluminum nitride nanotubes, wherein the sixth outer wall and the inner wall are covered with a carbon film, wherein the aluminum nitride nanotubes are heated in an ammonia gas stream for 0.5 to 1.2 hours. I will provide a.

  The invention of this application is, in the eighth aspect, in the method of manufacturing an aluminum nitride nanotube in which the outer wall and the inner wall of any one of the second to seventh are covered with a carbon film, and the flow rate of the inert gas is in the range of 80 to 150 sccm. A method for producing an aluminum nitride nanotube is provided.

  The ninth aspect of the invention of this application is the method for producing an aluminum nitride nanotube in which the outer wall and the inner wall of any one of the second to eighth aspects are covered with a carbon film, wherein the flow rate of ammonia gas is in the range of 150 to 250 sccm. A method for producing an aluminum nitride nanotube is provided.

  According to the invention of this application, a carbon film is grown on an outer wall and an inner wall of an aluminum nitride nanotube, and the outer wall and the inner wall are carbon films that are expected to be applied to fields such as new optoelectronics and field emission materials. Covered aluminum nitride nanotubes are obtained.

  The aluminum nitride nanotubes whose outer wall and inner wall of the invention of this application are covered with a carbon film are both covered with a carbon film, the outer diameter is 45 to 50 nanometers, and the thickness of the carbon film is It has a thickness of 2 to 3 nanometers and a wall thickness of 10 to 15 nanometers.

  The aluminum nitride nanotubes whose outer wall and inner wall are covered with a carbon film are manufactured by heating a mixture of alumina powder and carbon nanotubes in an inert gas stream, then switching the inert gas to ammonia gas and continuing heating. The

  Specifically, a mixture of alumina powder and carbon nanotubes is put into a graphite crucible, this graphite crucible is placed in a vertical high frequency induction heating furnace, and the pressure is reduced to 2 to 3 Torr, and then an inert gas such as argon gas is introduced. While flowing, heat the contents of the crucible. After this, the inert gas is switched to ammonia gas and heating is continued. By this series of heating, black wool-like substances are deposited on the inner wall of the graphite crucible. This black wool-like material has an outer diameter of 45 to 50 nanometers, a carbon film thickness of 2 to 3 nanometers, and a wall thickness of 10 to 15 nanometers of aluminum nitride nanotubes whose outer and inner walls are covered with a carbon film. It is.

In the production of the aluminum nitride nanotubes whose outer wall and inner wall are covered with the carbon screen, the weight ratio of the alumina powder to the carbon nanotubes is preferably in the range of 4: 1 to 3: 1. If the alumina powder is more than the above range, a part of the alumina powder remains unreacted without being reduced. If the alumina powder is less than the above range, unreacted carbon is mixed in the product.

The flow rate of an inert gas such as argon gas is preferably in the range of 80 to 150 sccm. A sufficiently inert atmosphere is maintained at 150 sccm. Below 80 sccm, it is not sufficient to maintain an inert atmosphere. The heating temperature in the inert gas stream is preferably in the range of 1450 to 1600 ° C. The reduction reaction of alumina proceeds sufficiently at 1600 ° C. The reaction does not proceed sufficiently at temperatures below 1450 ° C. The heating time in the inert gas stream is preferably in the range of 0.4 to 1 hour. In 1 hour, the reduction reaction of alumina proceeds sufficiently. If the heating time is less than 0.4 hours, the reaction is not completely completed.

The flow rate of ammonia gas is preferably in the range of 150 to 250 sccm. For flow rates over 250sccm,
Formation and growth of the aluminum nitride nanotubes are in a non-equilibrium state, and crystal defects are generated in the grown aluminum nitride nanotubes. If the flow rate is lower than 150 sccm, the amount of ammonia vapor is not sufficient, so that formation and growth of aluminum nitride nanotubes are not performed sufficiently. The heating temperature in the ammonia gas stream is preferably in the range of 1300 to 1600 ° C. The final product is fully formed at 1600 ° C. When the temperature is lower than 1300 ° C., the reaction rate for forming aluminum nitride and the crystal growth rate of the aluminum nitride nanotubes covered with the carbon film become slow. The heating time in the ammonia stream is preferably in the range of 0.5 to 1.2 hours. The formation and growth of the final composite nanotube proceeds sufficiently in 1.2 hours. In less than 0.5 hour, the growth of the composite nanotube is not completed.

Wako Pure Chemical Industries, Ltd. 3g alumina powder (purity 99.9%) and known method (Cheng C. Tang, et al .; Carbon, 2002, Vol. 40, p. 2497 to 2502) A mixture of 0.5 g of the carbon nanotubes (a few micrometers long, 40-55 nanometers in diameter) was placed in a graphite crucible. This graphite crucible is placed in the center of the vertical high frequency induction heating furnace, the inside of the vertical high frequency induction heating furnace is depressurized to 2-3 Torr, and then argon gas is added at 100 sccm.
The contents of the crucible were heated to 1600 ° C. for 1 hour while flowing at a flow rate of. Thereafter, the argon gas was switched to ammonia gas and heated to 1600 ° C. for 1 hour while flowing at a flow rate of 200 sccm. 0.4 g of a black wool-like substance was deposited on the inner wall of the graphite crucible.

  FIG. 1 shows the X-ray diffraction pattern of the black deposit. The black deposit was confirmed to be hexagonal aluminum nitride having lattice constants a = 3.114 Å and c = 4.986 Å.

  FIG. 2 shows a photograph of a low magnification transmission electron microscope image of the black deposit. It can be seen that nanotubes having a length of several micrometers or more, an outer diameter of 45 to 50 nanometers, and a wall thickness of 13 nanometers are formed.

  FIG. 3 shows a photograph of a high-resolution transmission electron microscope image of the black deposit. It can be seen from this photograph that a thin layer of 2 to 3 nanometers is formed on the outer wall and the inner wall of the tube.

FIG. 4 shows the X-ray energy diffusion spectrum of the black deposit. The chemical composition was 48.1 atom% aluminum, 46.3 atom% nitrogen, 4.6 atom% carbon, and 1 atom% oxygen. The atomic ratio of aluminum to nitrogen was 1: 0.97, confirming that the aluminum nitride had a stoichiometric composition. The detected 4.6 atom% of carbon corresponds to a thin film layer on the outer wall and inner wall of the nanotube.

FIG. 5 shows a photoluminescence spectrum of a black deposit measured at room temperature using a 325 nm He—Cd laser as an excitation light source. Blue light emission having an emission band from 350 nm to 550 nm and a central band of 412 nm is exhibited.

  As described in detail above, the invention of this application has realized a novel aluminum nitride nanotube whose outer wall and inner wall are covered with a carbon film. This nanotube is expected to be applied to fields such as optoelectronics and field emission materials. The

It is a pattern of the X-ray diffraction of the black deposit obtained in the Example. It is a photograph of the low magnification transmission electron microscope image of the black deposit obtained in the Example. It is a photograph of the high resolution transmission electron microscope image of the black deposit obtained in the Example. It is a figure of the X-ray energy-diffusion spectrum of the black deposit obtained in the Example. It is a figure of the photoluminescence spectrum in room temperature of the black deposit obtained in the Example.

Claims (9)

  Both the outer wall and inner wall of the aluminum nitride nanotube are covered with a carbon film, the outer diameter is 45-50 nanometers, the carbon film thickness is 2-3 nanometers, and the wall thickness is 10-15 nanometers. An aluminum nitride nanotube whose outer and inner walls are covered with a carbon film.   Production of aluminum nitride nanotubes whose outer and inner walls are covered with a carbon film, wherein a mixture of alumina powder and carbon nanotubes is heated in an inert gas stream and then the inert gas is switched to ammonia gas and then heated. Method.   The method for producing aluminum nitride nanotubes, wherein the outer wall and the inner wall are covered with a carbon film, wherein the weight ratio of the alumina powder and the carbon nanotube is in the range of 4: 1 to 3: 1.   The method for producing aluminum nitride nanotubes, wherein the outer wall and the inner wall are covered with a carbon film, which is heated at a temperature in the range of 1450 to 1600 ° C in an inert gas stream. The manufacturing method of the aluminum nitride nanotube by which the outer wall and inner wall were covered with the carbon film of Claim 4 heated for 0.4 to 1 hour in inert gas stream.   The method for producing aluminum nitride nanotubes, wherein the outer wall and the inner wall are covered with a carbon film according to any one of claims 2 to 5, wherein heating is performed at a temperature in the range of 1300 to 1600 ° C in an ammonia gas stream.   The method for producing aluminum nitride nanotubes, wherein the outer wall and the inner wall are covered with a carbon film, which is heated in an ammonia gas stream for 0.5 to 1.2 hours. The method for producing aluminum nitride nanotubes, wherein the outer wall and the inner wall are covered with a carbon film according to any one of claims 2 to 7, wherein the flow rate of the inert gas is in the range of 80 to 150 sccm. The method for producing aluminum nitride nanotubes, wherein the outer wall and the inner wall are covered with a carbon film according to any one of claims 2 to 8, wherein the flow rate of ammonia gas is in the range of 150 to 250 sccm.