Carbon compounds and their manufacturing methods

Abstract

To provide a carbon compound having a new crystal structure capable of providing new characteristics not found in the conventional crystal structures.MEANS FOR SOLVING THE PROBLEM: A carbon compound of the present invention comprises a phase of spinel-type crystal structure formed on a crystalline substrate and crosslinking the substrate.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a carbon compound and a method for producing the same. [Background technology]

[0002] Currently, fullerenes and carbon nanotubes are attracting attention as carbon materials of the future, and although the atoms that make up these materials are the same carbon (C) as graphite and diamond, they have a spherical or tubular structure in which the atoms are bonded in closed bonds. In particular, carbon nanotubes, which have a nano-sized tubular bond structure, are expected to be used in semiconductor device materials, battery materials, conductive materials, hydrogen storage materials, capacitor materials, superhard materials, pharmaceuticals, resist materials, and more.

[0003] Moreover, a typical structure among fullerenes is one in which 60 atoms are bonded together in the shape of a soccer ball. In addition to the uses mentioned above, it is expected to find applications in superconducting materials and ultrahard materials. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Introduction to Carbon (https: / / www.toyotanso.co.jp / introduction / future.html) Summary of the Invention [Problem to be solved by the invention]

[0005] However, the only known crystal structures of carbon compounds at present are those with graphite and diamond structures, in addition to the special structures such as fullerene and carbon nanotubes mentioned above, and there are naturally limitations to the improvement of their properties.

[0006] An object of the present invention is to provide a carbon compound with a novel crystal structure that can provide novel properties not available in conventional crystal structures. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention is as follows. (1) The present invention comprises a crystalline silicon substrate and a multilayer film of carbon, the C-axis direction of silicon constituting the crystalline silicon substrate and the multilayer film of carbon are arranged in parallel, and the multilayer film of carbon is Formed on a crystalline substrate ,vinegar Contains a phase with a Pinel type crystal structure The crystalline silicon substrate and the carbon multilayer are cross-linked. Characterized in that Laminate . (2) The stack according to (1), wherein the c-axis direction of the silicon is parallel to the stacking direction of the carbon multilayer film. ( 3 ) A structure in which graphite is laminated in multiple stages on the side opposite to the substrate, continuous with the spinel type crystal structure phase. Phase (1) Or (2) Described in Laminate . ( 4 ) Resistivity at thicknesses of 10 -5 ~10 -10 (1) characterized in that the resistance is Ω·m. Any one of ~(3) Described in Laminate . ( 5 ) The resistivity decreases with increasing thickness of the carbon compound, 4 ) Laminate . ( 6 A cathode on which an electron source is disposed and a crystalline silicon a step of disposing an anode on which a substrate is disposed; a step of disposing a gate electrode on the cathode side between the cathode and the anode and a step of disposing an acceleration electrode on the anode side; and a step of disposing an acetylene-based Hydrocarbons a step of flowing an acetylene-based gas, decomposing the acetylene-based gas with electrons emitted from the electron source and a voltage applied to the gate electrode to obtain at least one of ionized carbon and hydrocarbon; and accelerating the at least one of the carbon and hydrocarbon with a voltage applied to the acceleration electrode to obtain at least one of the ionized carbon and hydrocarbon. Crystalline siliconand irradiating the substrate. Laminate Manufacturing method 。 Effect of the Invention

[0008] As described above, according to the present invention, it is possible to provide a carbon compound having a novel crystal structure that can provide new properties not available in conventional crystal structures. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of an apparatus for producing a carbon compound according to an embodiment. [Diagram 2] 2 is a SEM photograph of a carbon compound in an example. [Diagram 3] 1 is an electron beam transmission image of a carbon compound in an example. [Figure 4] 1 is an electron beam transmission image of a carbon compound in an example. [Diagram 5] FIG. 2 is a diagram of an apparatus for measuring electrical properties of a carbon compound in the examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, details and other features of the present invention will be described based on embodiments. (Carbon compounds) The carbon compound of the present invention is formed on a crystalline substrate and contains a phase of a spinel-type crystal structure bridging the substrate. Since no carbon compound with such a structure has existed in the past, it is expected to exhibit various properties.

[0011] For example, due to its spinel crystal structure, it is expected to exhibit magnetism that has not existed in conventional carbon.

[0012] Changes can also be seen in the electrical properties. For example, the resistivity at a thickness of 100 nm or less is 10 -5 ~10 -10It shows that the resistivity is about Ω·m, which is similar to that of metallic aluminum, and has metallic properties. The minimum thickness at which this resistivity is exhibited is, for example, 20 nm.

[0013] Furthermore, the carbon compound of the present invention has a decrease in resistivity as the thickness increases, and exhibits similar properties to a thin metal film, and thus has metallic properties. For example, the resistivity decreases by 10 -5 ~10 -10 It decreases to Ω·m.

[0014] At present, the above-mentioned properties, particularly the metallic properties, are considered to depend not only on the spinel-type crystal structure in the carbon compound, but also on the property of the carbon compound that the carbon compound contains a polycarbon phase having a structure in which graphite is laminated in multiple layers on the side opposite the substrate, continuous with the spinel-type crystal structure phase.

[0015] In the present invention, the term "crosslinking" does not mean a reaction that mainly occurs in polymer chemistry, in which polymers are linked together and their physical and chemical properties are changed, but rather means a bonding state in a broad sense in which the crystal structures of the polymers are bonded together as if they were bridged, as is clear from the results of the following examples.

[0016] (Method of producing carbon compounds) Next, an example of the method for producing the carbon compound will be described. Fig. 1 is a schematic diagram showing an example of an apparatus 10 for producing a carbon compound.

[0017] 1, a carbon compound production apparatus 10 of this embodiment has a cathode 11 and an anode 12 disposed so as to face the cathode 11. An electron source 14 is disposed on the cathode 11, with an ITO transparent conductive film 13 serving as an electrode. In addition, a crystalline substrate 15 for forming a target carbon compound is disposed on the anode 12.

[0018] Furthermore, between the cathode 11 and the anode 12, a gate electrode 16 is disposed on the cathode 11 side, and an acceleration electrode 17 is disposed on the anode 12 side.

[0019] The cathode 11, anode 12, gate electrode 16 and acceleration electrode 17 can be made of a metal having excellent electrical conductivity, such as aluminum, gold, silver, or copper, or iron, cobalt, nickel, tungsten, molybdenum, or alloys thereof having excellent heat resistance.

[0020] The electron source 14 is also not particularly limited, but is preferably made of carbon nanotubes from the viewpoint of stable electron emission, and is particularly preferably made of highly crystalline single-walled carbon nanotubes.

[0021] The substrate 15 is also not particularly limited as long as it has crystallinity, and a semiconductor such as silicon or a ceramic such as zinc oxide can be used.

[0022] As will be described below, since an acetylene-based gas is used in the production of carbon compounds, it is preferable that the entire production apparatus 10 is disposed in a vessel such as a vacuum chamber as necessary.

[0023] The size of the manufacturing apparatus 10 can be set appropriately, for example, the distance between the cathode 11 and the anode 12 can be 0.1 to 1.0 cm, the distance between the cathode 11 and the gate electrode 14 can be 0.005 to 0.02 cm, and the distance between the anode 12 and the acceleration electrode 17 can be 0.1 to 0.5 cm.

[0024] After preparing the manufacturing apparatus 10 as described above, an acetylene-based gas 18 is flowed between the cathode 11 and the anode 12, more specifically, between the gate electrode 14 and the acceleration electrode 17. The acetylene-based gas 18 means a so-called acetylene-based hydrocarbon, which means a substance having a triple bond between carbon atoms. Specific examples include acetylene, propyne, and 1-butyne, but acetylene is generally used because it is the most reactive, inexpensive, and easily available.

[0025] The acetylene gas 18 is supplied at a predetermined flow rate, and simultaneously, a current of, for example, 70 nA / cm is generated from the carbon nanotube 14. 2 When electrons are emitted at the above current density (dose amount) and a voltage of, for example, 18 to 40 V is applied to the gate electrode 16, the acetylene-based gas 18 is decomposed and becomes ionized carbon or hydrocarbons.

[0026] Next, the ions are accelerated by applying a voltage of, for example, 200 to 600 V to acceleration electrode 17, and are irradiated onto substrate 15. Then, a carbon compound containing at least the phase having a spinel type crystal structure described above is formed on substrate 15.

[0027] As described above, according to the present embodiment, a cathode having an electron source and an anode having a substrate are opposed to each other, a gate electrode and an acceleration electrode are disposed between them, an acetylene-based gas is decomposed by the gate electrode, and the ions obtained by the decomposition by the acceleration electrode are accelerated and irradiated toward the substrate. This is a simple operation that utilizes the principle of field electron emission, and thus a carbon compound having a desired phase of a spinel-type crystal structure can be obtained. EXAMPLES

[0028] Example 1 A carbon compound having a spinel-type crystal structure phase was produced using a production apparatus 10 as shown in FIG.

[0029] Cathode 11 and anode 12 were made of metal or semiconductor substrates, and gate electrode 16 and acceleration electrode 17 were made of processed stainless steel plates. The distance between cathode 11 and anode 12 was set to 0.35 cm, the distance between cathode 11 and gate electrode 16 was set to 0.01 cm, and the distance between anode 12 and acceleration electrode 17 was set to 0.17 cm.

[0030] The electron source 14 has an electron emission size of 15×15 mm. 2The voltage applied to gate electrode 16 was set to 22 V. Furthermore, the voltage applied to acceleration electrode 17 was set to 500 V.

[0031] In this embodiment, the entire manufacturing apparatus 10 was housed in a vacuum chamber, and acetylene gas was introduced so that the internal pressure was 1.6 Pa. Furthermore, zinc oxide formed by wet synthesis was used as the substrate 15.

[0032] An SEM photograph of the obtained carbon compound is shown in Figure 2. The SEM photograph shown in Figure 2 was taken of a test piece in which the obtained carbon compound was embedded in resin and then flake-processed by focused ion beam processing.

[0033] As is clear from Figure 2(a), although fine gaps can be seen inside the carbon compound, it is understood that it is macroscopically elliptical. Also, Figure 2(b) is an enlarged view of the white circle part in Figure 2(a), and it can be seen that the zinc oxide particles, which were originally granular, are selectively cross-linked in the crystal C-axis direction by the non-equilibrium excitation reaction field, resulting in elliptical particles. It can also be seen that a carbon film is coated between these elliptical zinc oxide particles.

[0034] FIG. 3 is a transmission image of the crystal structure near the interface between zinc oxide and the carbon film, observed using a high-resolution electron microscope (HRTEM: manufactured by JEOL Ltd.) with an acceleration voltage of 300 kV.

[0035] Figure 3(a) shows a high-resolution electron transmission image of the interface between zinc oxide and the carbon film. It shows that a carbon film of about 20 nm has been formed on the zinc oxide surface, and a clear interface between the zinc oxide and the carbon film can be confirmed.

[0036] Figures 3(b) and 3(c) show the diffraction pattern and Fourier transform image of the zinc oxide side. From the images in Figures 3(a) to (c), it was found that the C-axis direction of the zinc oxide and the carbon multilayer film were aligned parallel to each other.

[0037] Furthermore, the diffraction pattern of the multilayer film was imaged and its Fourier transform image was obtained (see Figure 4(d)). As a result, it was found that the multilayer film has a spinel type crystal structure.

[0038] At this time, as described above, the phase having a spinel type crystal structure and the C-axis of zinc oxide are bonded in parallel to each other, and therefore it is found that the phase and zinc oxide are cross-linked.

[0039] Furthermore, as is clear from Figure 3(e), the carbon film away from the zinc oxide surface was found to be a polycarbon phase in which graphite layers were stacked in multiple stages.

[0040] Example 2 A carbon compound was formed under the same conditions using the same production apparatus 10 as in Example 1, except that the substrate was changed from zinc oxide to a silicon substrate having a thickness of 0.625 mm.

[0041] FIG. 4 is a transmission image of the crystal structure near the interface between zinc oxide and the carbon film, observed using a high-resolution electron microscope (HRTEM: manufactured by JEOL Ltd.) with an acceleration voltage of 300 kV.

[0042] As is clear from Fig. 4, in this embodiment, it was found that the C-axis direction of silicon and the multilayer film of carbon were aligned parallel to each other, as in the embodiment 1. The diffraction pattern of the multilayer film was imaged and its Fourier transform image was obtained. As a result, it was found that the multilayer film has a spinel type crystal structure.

[0043] In addition, since the phase having a spinel type crystal structure and the C-axis of zinc oxide are bonded in parallel to each other, it is understood that the phase and silicon are bridged.

[0044] Furthermore, when the resistivity of the carbon compound having a spinel-type crystal structure phase obtained as described above was measured using the device shown in FIG. 5, it was found to be approximately 10 -3 ~10 -5It showed a resistivity of Ω·cm, which is as low as that of aluminum, meaning it had high conductivity.

[0045] In addition, when the thickness increases from 0.03 μm to 1.2 μm, the resistivity increases by 10 -5 Ω cm to 10 -8 It was confirmed that the resistivity decreased to Ω·cm.

[0046] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0047] 10. Carbon compound manufacturing equipment 11 Cathode 12 Anode 13 ITO transparent conductive film 14 Electron source 15 Substrate 16 Gate electrode 17 Acceleration electrode 18 Acetylene gas

Claims

1. A multilayered film comprising a crystalline silicon substrate and carbon, the C-axis direction of silicon constituting the crystalline silicon substrate and the multilayer film of carbon are aligned parallel to each other; the carbon multilayer film is formed on the crystalline silicon substrate and includes a phase having a spinel type crystal structure; The crystalline silicon substrate and the carbon multilayer are crosslinked.

2. The laminate described in claim 1, wherein the C-axis direction of the silicon and the stacking direction of the carbon multilayer film are arranged parallel to each other.

3. 3. The laminate according to claim 1, further comprising a phase having a structure in which graphite is laminated in multiple stages on the side opposite to the substrate, the phase being continuous with the phase having the spinel type crystal structure.

4. Resistivity at a thickness of 100 nm or less is 10 -5 ~10 -10 The laminate according to any one of claims 1 to 3, characterized in that the elastic modulus is Ω·m.

5. 4. A method according to claim 3, wherein the resistivity decreases with increasing thickness of the carbon compound.

5. The laminate according to any one of 1 to 4.

6. providing a cathode having an electron source disposed thereon and an anode having a crystalline silicon substrate disposed opposite the cathode; a step of disposing a gate electrode on the cathode side and an acceleration electrode on the anode side between the cathode and the anode; a step of flowing an acetylene-based hydrocarbon between the gate electrode and the acceleration electrode, and decomposing the acetylene-based gas by electrons emitted from the electron source and a voltage applied to the gate electrode to obtain at least one of ionized carbon and hydrocarbon; and accelerating at least one of the carbon and the hydrocarbon by a voltage applied to the acceleration electrode and irradiating the crystalline silicon substrate of the anode.

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