Negative thermal expansion material, method for manufacturing a negative thermal expansion material, composite material, and component

Abstract

To provide a new negative thermal expansion material. [Solution] The negative thermal expansion material is Co 3-x A x B 1-y T y O z The compound comprises a sintered body of a compound represented by (A contains at least one element selected from Li, Mg, Ca, Sr, Ba, Al, Si, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, In, Sn, Sb, La, Ce, Hf, Ta, W, Bi, and T contains at least one element selected from C, Al, Mg, Si, Ga, Ge, satisfying 0≦x≦3, 0≦y≦1, and 4≦z≦6), which exhibits negative thermal expansion in at least part of the temperature range of 100K to 700K.

Description

[Technical Field]

[0001] This disclosure relates to negative thermal expansion materials, methods for manufacturing negative thermal expansion materials, composite materials, and components. [Background technology]

[0002] It is generally known that materials expand with increasing temperature. However, the advanced development of industrial technology in recent years has led to demands to control even the thermal expansion that is inherent to solid materials. -5 Even a small rate of change, such as a small one from a general perspective, can be a major problem in fields such as semiconductor device manufacturing, where nanometer-level precision is required, or in precision equipment where even slight distortion of components can have a significant impact on functionality. Furthermore, in devices that combine multiple materials, differences in the thermal expansion of each constituent material can lead to other problems such as interfacial delamination and disconnection.

[0003] On the other hand, negative thermal expansion materials are also known, in which the lattice volume decreases with increasing temperature (having a negative coefficient of thermal expansion). For example, β-Cu with a monoclinic crystal structure exhibits large negative thermal expansion over a wide temperature range. 1.8 Zn 0.2 V2O7 is known (see Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2019-210198 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, negative thermal expansion remains a rare phenomenon, and materials with negative thermal expansion properties that adequately meet industrial requirements are limited.

[0006] The present disclosure has been made in view of these circumstances, and one of the objects thereof is to provide a new negative thermal expansion material. Means for Solving the Problem

[0007] In order to solve the above problem, a negative thermal expansion material according to an aspect of the present disclosure is represented by general formula (1) Co 3-x A x B 1-y T y O z (wherein A contains at least one element selected from the group consisting of Li, Mg, Ca, Sr, Ba, Al, Si, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, In, Sn, Sb, La, Ce, Hf, Ta, W, and Bi, T contains at least one element selected from the group consisting of C, Al, Mg, Si, Ga, and Ge, and 0 ≤ x ≤ 3, 0 ≤ y ≤ 1, and 4 ≤ z ≤ 6 are satisfied), and exhibits negative thermal expansion in at least a part of the temperature range of 100K to 700K.

[0008] Another aspect of the present disclosure is a method for producing a negative thermal expansion material. The method comprises mixing raw materials of a compound represented by general formula (1) Co 3-x A x B 1-y T y O z (wherein A contains at least one element selected from the group consisting of Li, Mg, Ca, Sr, Ba, Al, Si, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, In, Sn, Sb, La, Ce, Hf, Ta, W, and Bi, T contains at least one element selected from the group consisting of C, Al, Mg, Si, Ga, and Ge, and 0 ≤ x ≤ 3, 0 ≤ y ≤ 1, and 4 ≤ z ≤ 6 are satisfied), and sintering the mixture, wherein the obtained negative thermal expansion material exhibits negative thermal expansion in at least a part of the temperature range of 100K to 700K.

[0009] Still another aspect of the present disclosure is a composite material. The composite material comprises the above negative thermal expansion material and a positive thermal expansion material having a positive linear expansion coefficient.

[0010] Still another aspect of the present disclosure is a component. This component comprises the negative thermal expansion material described above, or a composite material including the above negative thermal expansion material and a positive thermal expansion material having a positive linear expansion coefficient.

Effects of the Invention

[0011] According to the present disclosure, a novel negative thermal expansion material can be provided.

Brief Description of Drawings

[0012] [Figure 1] It is a figure showing an X-ray diffraction pattern of the negative thermal expansion material of the present disclosure. [Figure 2] It is a figure showing an X-ray diffraction pattern of the negative thermal expansion material of the present disclosure. [Figure 3] It is a figure showing an X-ray diffraction pattern of the negative thermal expansion material of the present disclosure. [Figure 4] It is a figure showing an X-ray diffraction pattern of the negative thermal expansion material of the present disclosure. [Figure 5] It is a figure showing an X-ray diffraction pattern of the negative thermal expansion material of the present disclosure. [Figure 6] It is a figure showing an X-ray diffraction pattern of the negative thermal expansion material of the present disclosure. [Figure 7] It is a figure showing linear thermal expansion of the negative thermal expansion material of the present disclosure. [Figure 8] It is a figure showing linear thermal expansion of the negative thermal expansion material of the present disclosure. [Figure 9] It is a figure showing linear thermal expansion of the negative thermal expansion material of the present disclosure. [Figure 10] It is a figure showing linear thermal expansion of the composite material of the present disclosure. [Figure 11] It is a figure showing particle size distribution of powder of the negative thermal expansion material of the present disclosure.

Mode for Carrying Out the Invention

[0013] The negative thermal expansion material according to the embodiment of the present disclosure is represented by general formula (1): Co 3-x A x B 1-y T y O zThe compound comprises a sintered body of a compound represented by (A contains at least one element selected from Li, Mg, Ca, Sr, Ba, Al, Si, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, In, Sn, Sb, La, Ce, Hf, Ta, W, Bi, and T contains at least one element selected from C, Al, Mg, Si, Ga, Ge, satisfying 0≦x≦3, 0≦y≦1, and 4≦z≦6), which exhibits negative thermal expansion in at least part of the temperature range of 100K to 700K.

[0014] Co3BO5 has orthorhombic symmetry and its space group is Pbam. When Co3BO5 is heated to 300-550K, the crystal structure is preserved, but significant changes occur in the crystallographic parameters. Specifically, the c-axis expands and the a-axis contracts during heating (e.g., N. Kazak et al., Dalton Trans. 51 (2022) 6345-6357). The inventors conceived that such thermal deformation of a highly anisotropic unit cell causes positive thermal expansion of the unit cell volume v, while causing negative thermal expansion in the sintered body. They also conceived that substitution of Co or B sites changes the temperature range in which the sintered body exhibits negative thermal expansion.

[0015] In other words, the negative thermal expansion of Co3BO5 is due to the anisotropic deformation of the crystal structure, which fills the voids in the sintered body, thus reducing the overall volume (e.g., K. Takenaka, J. Jpn. Soc. Powder Powder Metallurgy 67 (2020) 499-504). This "material structure effect" depends on the shape of the crystal grains and the size of the voids. By substituting some or all of the Co or B sites of Co3BO5 with another element, the atomic radius, the number of d electrons and valence electrons, etc., changes. These changes lead to changes in the crystal growth of the material, and as a result, the size of the crystal grains and voids that determine the material structure effect changes, which in turn is thought to change the magnitude and temperature range of the negative thermal expansion.

[0016] Thus, the manifestation of negative thermal expansion in compounds of general formula (1) is essentially dependent on the material microstructure effect of the sintered body. Therefore, it can be reasonably predicted that compounds having a similar crystal structure to Co3BO5, in which the Co and B sites are substituted with various elements in arbitrary compositional ratios, will also exhibit negative thermal expansion due to the material microstructure effect.

[0017] Generally, in metal borates, sp 2 The triangle of hybrid orbitals BO3 and sp 3 It is known that a wide variety of chemical compositions can be obtained because tetrahedra of hybridized orbitals BO4 are formed and these can be spatially bonded. Therefore, the Co and B sites of Co3BO5 can be substituted with a wide variety of elements in arbitrary compositional ratios, and it can be reasonably predicted that such compounds will have an orthorhombic crystal system and a Pbam space group, just like Co3BO5.

[0018] In general formula (1), x may be greater than 0, 0 or greater, 0.01 or greater, 0.02 or greater, 0.03 or greater, 0.04 or greater, 0.05 or greater, 0.06 or greater, 0.07 or greater, 0.08 or greater, 0.09 or greater, 0.1 or greater, 0.2 or greater, 0.3 or greater, 0.4 or greater, 0.5 or greater, 0.6 or greater, 0.7 or greater, 0.8 or greater, 0.9 or greater, 1 or greater, 1.1 or greater, 1.2 or greater, 1.3 or greater, 1.4 or greater, 1.5 or greater, 1.6 or greater, 1.7 or greater, 1.8 or greater, 1.9 or greater, 2 or greater, 2.1 or greater, 2.2 or greater, 2.3 or greater, 2.4 or greater, 2.5 or greater, 2.6 or greater, 2.7 or greater, 2.8 or greater, or 2.9 or greater. x may be less than 3, 3 or less, 2.9 or less, 2.8 or less, 2.7 or less, 2.6 or less, 2.5 or less, 2.4 or less, 2.3 or less, 2.2 or less, 2.1 or less, 2 or less, 1.9 or less, 1.8 or less, 1.7 or less, 1.6 or less, 1.5 or less, 1.4 or less, 1.3 or less, 1.2 or less, 1.1 or less, 1 or less, 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, 0.2 or less, or 0.1 or less.

[0019] In general formula (1), y may be greater than 0, 0 or more, 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, 0.5 or more, 0.6 or more, 0.7 or more, 0.8 or more, or 0.9 or more. y may also be less than 1, 1 or less, 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, 0.2 or less, or 0.1 or less.

[0020] In general formula (1), z may be 5. Due to the degree of compositional fluctuations that are generally possible in metal oxides and metal borates, z may be 4 or more, 4.1 or more, 4.2 or more, 4.3 or more, 4.4 or more, 4.5 or more, 4.6 or more, 4.7 or more, 4.8 or more, 4.9 or more, 5.1 or less, 5.2 or less, 5.3 or less, 5.4 or less, 5.5 or less, 5.6 or less, 5.7 or less, 5.8 or less, 5.9 or less, or 6 or less.

[0021] The negative thermal expansion material of this disclosure may have an orthorhombic crystal system and a Pbam space group, similar to Co3BO5. This makes it possible to provide a negative thermal expansion material in which the sintered body exhibits negative thermal expansion due to the material microstructure effect, similar to Co3BO5.

[0022] The negative thermal expansion material of this disclosure may contain two or more elements as A in general formula (1). In this case, the sum of the compositions of the elements contained as A may be denoted as x. The negative thermal expansion material of this disclosure may contain two or more elements as T in general formula (1). In this case, the sum of the compositions of the elements contained as T may be denoted as y.

[0023] The negative thermal expansion material of this disclosure exhibits negative thermal expansion in at least a portion of the temperature range between 100K and 700K. The negative thermal expansion material of this disclosure only needs to exhibit negative thermal expansion in at least a portion of the temperature range between 100K and 700K, and may also exhibit positive thermal expansion in a portion of the temperature range between 100K and 700K. The "at least a portion of the temperature range" may be any temperature range, for example, 1K, or 10K, 20K, 30K, 40K, 50K, and 100K.

[0024] The negative thermal expansion material of this disclosure may exhibit negative thermal expansion in the temperature range of 400K to 500K. The negative thermal expansion material of this disclosure may exhibit negative thermal expansion in the entire temperature range of 400K to 500K, and may not exhibit positive thermal expansion in the entire temperature range of 400K to 500K. The temperature range in which the negative thermal expansion material of this disclosure exhibits negative thermal expansion may be 300K or higher, 350K or higher, 400K or higher, or 450K or higher. The temperature range in which the negative thermal expansion material of this disclosure exhibits negative thermal expansion may be 600K or lower, 550K or lower, 500K or lower, 450K or lower, or 400K or lower.

[0025] The negative thermal expansion material of this disclosure exhibits negative thermal expansion even in the high-temperature range of approximately 550K, which is difficult for other negative thermal expansion materials to handle. Furthermore, the temperature range in which negative thermal expansion is exhibited can be controlled by controlling the elements and composition ratios that substitute for the Co and B sites. As will be described later, there are elements that shift the temperature range in which negative thermal expansion is exhibited towards higher temperatures (such as Ni and Hf) and elements that shift it towards lower temperatures (such as Cu), so the elements and composition ratios that substitute for the Co and B sites should be selected according to the application of the negative thermal expansion material. The negative thermal expansion material of this disclosure does not contain toxic elements such as Pb, so it has advantages in terms of environmental impact and can be widely used as a negative thermal expansion material.

[0026] Negative thermal expansion materials may be manufactured by a solid-phase reaction method or by a spray-drying method. In the former case, powders of raw materials such as oxides containing the constituent elements of the compound represented by general formula (1) are weighed in a specified molar ratio, mixed in an agate mortar and pestle, and then calcined in an alumina crucible. In the latter case, an aqueous solution containing at least one of the compound represented by general formula (1) and its raw materials, and at least one of an acid, salt, and organometallic compound is spray-dried. Negative thermal expansion materials produced by solid-phase reactions, etc., may be pulverized and then heated to recrystallize them.

[0027] The spray drying method yields particles with smaller particle sizes, a narrower particle size distribution, and an isotropic shape compared to conventional solid-phase reaction methods. This allows for powder pulverization with significantly less mechanical load compared to pulverizing large crystals obtained with conventional solid-phase reaction methods, resulting in a group of fine particles that maintain negative thermal expansion properties. Further adjustments to particle size and particle size distribution can be made by incorporating classification processes such as sieving.

[0028] The acid may be an organic acid or an inorganic acid. Examples of organic acids include citric acid and acetic acid. The salt may be a salt of an organic acid and an alkali, or a salt of an inorganic acid and an alkali. Examples of salts include metal nitrates, metal acetates, metal sulfates, metal chlorides, and metal fatty acids. Examples of organometallic compounds include metal alkoxides and metal acetylacetonates. An aqueous solution of the metal dissolved in nitric acid, hydrochloric acid, sulfuric acid, etc. may also be used.

[0029] When preparing an aqueous solution, the compound represented by general formula (1) itself may be dissolved, or the raw material of the compound represented by general formula (1) may be dissolved.

[0030] The negative thermal expansion material of this disclosure exhibits excellent negative thermal expansion properties even in the form of a fine powder. Therefore, it can effectively suppress the thermal expansion of components such as resin films, adhesives, interlayer fillers, and substrates that are expected to be used in the field of electronic devices at a size of several micrometers.

[0031] To suppress negative thermal expansion in such minute components, it is necessary not only for the average particle size of the negative thermal expansion material powder to be small, but also for there to be few coarse particles. From this perspective, the negative thermal expansion material powder is defined as having a volume frequency of 90% particle size (D 90 The inventors realized that it is appropriate to define it by the upper limit of ).

[0032] The powder of the negative thermal expansion material disclosed herein has a volume frequency of 90% particle size (D 90The volume frequency 90% particle size is 50 μm or less. The volume frequency 90% particle size is measured by the laser diffraction / scattering particle size distribution evaluation method. The volume frequency 90% particle size of the negative thermal expansion material of this disclosure may be 50 μm or less, 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, 20 μm or less, 19 μm or less, 18 μm or less, 17 μm or less, 16 μm or less, 15 μm or less, 14 μm or less, 13 μm or less, 12 μm or less, 11 μm or less, 10 μm or less, 9 μm or less, 8 μm or less, or 7 μm or less.

[0033] The powder of the negative thermal expansion material disclosed herein has a volume frequency of 90% particle size (D 90 ) may be 0.01 μm or larger, 0.05 μm or larger, 0.1 μm or larger, 0.2 μm or larger, 0.3 μm or larger, 0.4 μm or larger, 0.5 μm or larger, 0.6 μm or larger, 0.7 μm or larger, 0.8 μm or larger, 0.9 μm or larger, 1 μm or larger, 1.5 μm or larger, 2 μm or larger, 2.5 μm or larger, 3 μm or larger, 3.5 μm or larger, 4 μm or larger, 4.5 μm or larger, 5 μm or larger, 5.5 μm or larger, or 6 μm or larger.

[0034] In order to further enhance the effect of suppressing negative thermal expansion by mixing with minute components, the volume frequency of the negative thermal expansion material powder (D 50 The particle size may be 20 μm or less, 15 μm or less, 10 μm or less, 9 μm or less, 8 μm or less, 7 μm or less, 6 μm or less, 5 μm or less, or 4 μm or less.

[0035] Volume frequency of the central particle size (D) of the negative thermal expansion material powder disclosed herein 50 ) may be 0.01 μm or larger, 0.05 μm or larger, 0.1 μm or larger, 0.2 μm or larger, 0.3 μm or larger, 0.4 μm or larger, 0.5 μm or larger, 0.6 μm or larger, 0.7 μm or larger, 0.8 μm or larger, 0.9 μm or larger, 1 μm or larger, 2 μm or larger, or 3 μm or larger.

[0036] In order to further enhance the effect of suppressing negative thermal expansion by mixing with minute components, the volume frequency of the negative thermal expansion material powder of this disclosure is 10% particle size (D 10The particle size may be 15 μm or less, 10 μm or less, 9 μm or less, 8 μm or less, 7 μm or less, 6 μm or less, 5 μm or less, 4 μm or less, or 3 μm or less.

[0037] Volume frequency of the negative thermal expansion material powder in this disclosure 10% particle size (D 10 ) may be 0.01 μm or larger, 0.05 μm or larger, 0.1 μm or larger, 0.2 μm or larger, 0.3 μm or larger, 0.4 μm or larger, 0.5 μm or larger, 0.6 μm or larger, 0.7 μm or larger, 0.8 μm or larger, 0.9 μm or larger, 1 μm or larger, or 2 μm or larger.

[0038] The above numerical ranges may be any combination as long as the lower limit of the 90% volume frequency particle size is smaller than the upper limit of the 90% volume frequency particle size, the lower limit of the central volume frequency particle size is smaller than the upper limit of the central volume frequency particle size, the upper limit of the central volume frequency particle size is smaller than the upper limit of the 90% volume frequency particle size, and the lower limit of the central volume frequency particle size is smaller than the lower limit of the 90% volume frequency particle size.

[0039] The negative thermal expansion material powder of this disclosure may be produced by a solid-phase reaction method or a spray drying method, or by grinding the powder produced by the solid-phase reaction method or spray drying method with a planetary ball mill or the like.

[0040] The composite material of this disclosure includes the negative thermal expansion material and the positive thermal expansion material having a positive linear expansion coefficient. This makes it possible to realize a composite material in which volume changes with respect to temperature changes are suppressed.

[0041] The component of this disclosure comprises the above-mentioned negative thermal expansion material, or a composite material including the above-mentioned negative thermal expansion material and a positive thermal expansion material having a positive linear expansion coefficient. This makes it possible to realize a component in which volume change with respect to temperature changes is suppressed.

[0042] (Examples) A negative thermal expansion material represented by general formula (1) was synthesized using a solid-phase reaction method. Powders of Co3O4, H3BO3, and CuO were weighed in appropriate molar ratios, thoroughly mixed in a mortar, and then heated in an alumina crucible in air at a rate of 50°C / h, reaching 1223K for 24 hours. Subsequently, the temperature was lowered to 1023K at a rate of 5°C / h and maintained for 12 hours, after which it was rapidly cooled to room temperature at a rate of 250°C / h.

[0043] Figures 1 and 2 show Co 3-x A x The X-ray diffraction patterns of BO5 (A=Ni, Ca, Hf, Ti, x=0.2) are shown. Figures 3 and 4 show Co 3-x A x The X-ray diffraction patterns of BO5 (A=Cr,Sc,Mn,V) are shown. It has been shown that these are orthorhombic crystals with the same space group Pbam as Co3BO5. Figures 5 and 6 show Co3B synthesized by a similar method. 1-y T y The X-ray diffraction pattern of O5 (T=Si, y=0.2) is shown. Although it contains a small amount of Co3O4 as an impurity, it has been shown that an orthorhombic solid solution system with the same space group Pbam as Co3BO5 can be obtained.

[0044] Figure 7 shows Co3BO5 and Co 3-x A x This shows the linear thermal expansion of a sintered body of BO5 (A=Cu, x=0.1, 0.2, 0.3). Figure 8 shows the linear thermal expansion of Co3BO5 and Co 3-x A x This shows the linear thermal expansion of a sintered body of BO5 (A=Ni, x=0.2). Figure 9 shows the linear thermal expansion of Co3BO5 and Co 3-x A x Figures 7, 8, and 9 show the linear thermal expansion of a sintered body of BO5 (A=Hf, x=0.2). The linear thermal expansion ΔL / L on the vertical axis in Figures 7, 8, and 9 represents the change in length relative to the length L at 100K. The change in length was measured using a laser thermal expandometer (LIX-2: manufactured by ULVAC, Inc.). The slope of the linear thermal expansion, i.e., the temperature derivative, is the linear expansion coefficient α. For isotropic materials with no directional dependence, the linear thermal expansion essentially represents the volume thermal expansion, and the relationship ΔV / V = 3ΔL / L holds (V is volume).

[0045] Co3BO5 exhibits positive thermal expansion in the temperature range of 100K to 400K and negative thermal expansion in the temperature range of 400K to 480K. After observing near-zero thermal expansion in the temperature range of 480K to 500K, it again exhibits negative thermal expansion in the temperature range of 500K to 550K. A volume change of -0.43% was observed in the temperature range of 400K to 550K where negative thermal expansion was observed. In the temperature range where this negative thermal expansion was observed, the volume in the a-axis direction decreased, suggesting that the negative thermal expansion is caused by crystallographic anisotropic deformation.

[0046] As shown in Figure 7, replacing the Co site with Cu shifted the temperature range exhibiting negative thermal expansion to lower temperatures. The greater the amount of Cu, the greater the shift to lower temperatures. 2.8 Cu 0.2 The ΔV / V ratio for BO5 was -0.24% between 350K and 520K.

[0047] As shown in Figures 8 and 9, replacing the Co site with Ni or Hf shifted the temperature range exhibiting negative thermal expansion to the higher temperature side.

[0048] The changes in negative thermal expansion properties due to such elemental substitution are thought to be influenced by factors such as the ionic radius, d electron number, and electronic state of the element substituting the Co or B site, as well as the crystallographic parameters of the compound in which the Co or B site is substituted with another element.

[0049] Figure 10 shows the linear thermal expansion of a composite material made of Co3BO5 and Cu. 50% vol of Co3BO5 was mixed with Cu and subjected to discharge plasma sintering at 300°C for 1 minute using Syntex Lab (manufactured by SPS Syntex). This demonstrates that the positive thermal expansion of Cu is suppressed by Co3BO5.

[0050] Figure 11 shows the particle size distribution of Co3BO5 powder. The volume frequency of the powder is 90% particle size D. 90 The volume frequency center particle size is 6.35 μm, D 50 The particle size is 3.84 μm, with a volume frequency of 10% particle size D. 10 It was 2.08 μm.

[0051] The present disclosure has been described above based on embodiments. These embodiments are illustrative, and it will be understood by those skilled in the art that various modifications are possible in combinations of their components and processing processes, and that such modifications are also within the scope of the present disclosure.

Claims

1. General formula (1) Co ３－ｘ A ｘ B １－ｙ T ｙ O ｚ (A comprises a sintered body of a compound represented by (A comprises at least one element selected from Li, Mg, Ca, Sr, Ba, Al, Si, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, In, Sn, Sb, La, Ce, Hf, Ta, W, Bi, and T comprises at least one element selected from C, Al, Mg, Si, Ga, Ge, satisfying 0 ≤ x ≤ 3, 0 ≤ y ≤ 1, and 4 ≤ z ≤ 6.) It exhibits negative thermal expansion in at least a portion of the temperature range of 100K to 700K. Negative thermal expansion material.

2. It exhibits negative thermal expansion in the temperature range of 400K to 500K. The negative thermal expansion material according to claim 1.

3. The crystal system is orthorhombic. The negative thermal expansion material according to claim 1.

4. The space group is Pbam. The negative thermal expansion material according to claim 3.

5. Increasing x shifts the temperature range where negative thermal expansion occurs towards higher temperatures. The negative thermal expansion material according to any one of claims 1 to 4.

6. Increasing x shifts the temperature range where negative thermal expansion occurs towards lower temperatures. The negative thermal expansion material according to any one of claims 1 to 4.

7. Volume frequency 90%: Particle size 40 μm or less The negative thermal expansion material according to any one of claims 1 to 4.

8. The volume frequency central particle size is 10 μm or less. The negative thermal expansion material according to any one of claims 1 to 4.

9. General formula (1) Co ３－ｘ A ｘ B １－ｙ T ｙ O ｚ comprising the step of mixing raw material substances of a compound represented by formula (A contains at least one element selected from the group consisting of Li, Mg, Ca, Sr, Ba, Al, Si, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, In, Sn, Sb, La, Ce, Hf, Ta, W and Bi, T contains at least one element selected from the group consisting of C, Al, Mg, Si, Ga and Ge, and 0≦x≦3, 0≦y≦1, 4≦z≦6 are satisfied) and sintering the mixture, It exhibits negative thermal expansion in at least a portion of the temperature range of 100K to 700K. A method for manufacturing a negative thermal expansion material.

10. A negative thermal expansion material according to any one of claims 1 to 4, A positive thermal expansion material having a positive coefficient of linear expansion, A composite material possessing the following characteristics.

11. A negative thermal expansion material according to any one of claims 1 to 4, or A composite material comprising a negative thermal expansion material according to any one of claims 1 to 4 and a positive thermal expansion material having a positive linear expansion coefficient. A component equipped with the following features.

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