A CaTiO3-based oxide high infrared radiation material and preparation method thereof

Abstract

The invention discloses a CaTiO3-based oxide high infrared radiation material and a preparation method thereof, and relates to the field of infrared radiation technology. The chemical formula is: Ca 1‑x RE x TiO 3‑δ , where RE is a rare earth element, 0≤x≤0.5, 0≤δ≤0.5. The preparation process is as follows: (1) CaTiO3 is added to anhydrous ethanol, and electromagnetic stirring is performed for 5 to 10 minutes to obtain suspension A; (2) rare earth oxide is added to suspension A, and electromagnetic stirring is performed for 1 to 2 hours to obtain suspension B; (3) suspension B is transferred to a drying oven, kept warm at 80°C for 1 to 2 hours, and dried to obtain a mixed powder of CaTiO3 and rare earth oxide; (4) the mixed powder is pre-pressed and molded, sintered and kept warm to obtain a CaTiO3-based oxide high infrared radiation material. The preparation process of the present invention is simple, the cost is low, and the obtained material has good infrared radiation performance.

Description

Technical Field

[0001] The present invention relates to the field of integrated optical devices, and in particular to an ultra-short thin-film lithium niobate phase modulator for sensing and a working method thereof. Background Art

[0002] High infrared radiation materials refer to materials that radiate a large amount of infrared electromagnetic wave energy after absorbing heat. High infrared radiation materials can realize infrared heating, radiation heat protection, photobiomodulation and other functions, and are widely used in food drying, electronic heat dissipation, spacecraft protection, medical diagnosis and treatment, etc. The infrared radiation characteristics of high infrared radiation materials are expressed by the radiation emittance, according to the Stefan-Boltzmann law: ,in is the radiation emittance of the material surface; σ is the Stefan-Boltzmann constant; T is the thermodynamic temperature; ε It is the emissivity of the material. Therefore, to improve the infrared radiation characteristics of the infrared radiation material, it is necessary to improve the infrared emissivity of the material.

[0003] CaTiO3 is a metal perovskite oxide with the advantages of good stability, rich content of constituent elements, environmental friendliness, low cost and suitability for large-scale production. Due to its excellent dielectric, catalytic, optical and thermoelectric properties, it can be widely used in electronic devices, photocatalysis, thermoelectricity and other fields. However, there are few studies related to its infrared radiation, which is basically blank.

[0004] Therefore, the present invention provides a CaTiO3-based oxide high infrared radiation material and a preparation method thereof. Summary of the invention

[0005] The purpose of the present invention is to provide a CaTiO3-based oxide high infrared radiation material and a preparation method thereof, so as to obtain a CaTiO3-based ceramic sheet with infrared radiation performance.

[0006] To achieve the above object, the present invention provides a CaTiO3-based oxide high infrared radiation material, the specific chemical formula of which is: Ca 1-x RE x TiO 3-δ , where RE is a rare earth element, x is the ratio of rare earth element doping, 0<x≤0.5; δ indicates the presence of oxygen vacancies in CaTiO3 oxide, 0≤δ≤0.5.

[0007] Preferably, the rare earth element is one of La and Ce.

[0008] The present invention also provides a method for preparing the above-mentioned CaTiO3-based oxide high infrared radiation material, comprising the following steps:

[0009] (1) Add CaTiO3 into anhydrous ethanol and stir with electromagnetic stirring to obtain suspension A;

[0010] (2) adding rare earth oxide to suspension A and stirring with electromagnetic field to obtain suspension B;

[0011] (3) The suspension B is transferred into a drying oven and dried to obtain a mixed powder of CaTiO3 and rare earth oxides;

[0012] (4) The mixed powder is subjected to pre-pressing and molding, and sintering and heat preservation to obtain a CaTiO3-based oxide high infrared radiation material.

[0013] Preferably, the electromagnetic stirring time in step (1) is 5 to 10 minutes; and the electromagnetic stirring time in step (2) is 1 to 2 hours.

[0014] Preferably, in step (3), drying is performed at 80° C. for 1 to 2 hours.

[0015] Preferably, the specific operation of step (4) is: pre-pressing the mixed powder, moving it into a muffle furnace for sintering and heat preservation, and obtaining Ca 1-x RE x TiO3-based oxide high infrared radiation material.

[0016] Preferably, the specific operation of step (4) is: pre-pressing the mixed powder into a shape and transferring it into a crucible buried with carbon powder, sintering and heat-insulating in a muffle furnace to obtain Ca 1-x RE x TiO 3-δ1 Oxide-based high infrared radiation materials.

[0017] Preferably, the sintering heating rate is 5°C / min, and after sintering, the temperature is kept at 1400-1500°C for 6 hours.

[0018] Preferably, the specific operation of step (4) is: putting the mixed powder into a graphite mold, sintering and heat-insulating in a vacuum hot pressing furnace to obtain Ca 1-x RE x TiO 3-δ2 Oxide-based high infrared radiation materials.

[0019] Preferably, the vacuum degree is ≤1 Pa, the pressure is 1-20 MPa, and after sintering, the temperature is kept at 1400-1500° C. for 3 hours.

[0020] Through high-temperature sintering, CaTiO3 is densified and lattice defects are generated, forming atomic gaps. At the same time, under high temperature, the thermal vibration of crystal atoms intensifies, so that some atoms obtain high enough energy to perform thermal diffusion. Due to thermal diffusion, the doped impurity atoms enter the CaTiO3 crystal and occupy the atomic vacancies generated by thermal vibration, and finally obtain doped CaTiO3 materials.

[0021] Therefore, the present invention provides a CaTiO3-based oxide high infrared radiation material and a preparation method thereof. By controlling the content of doping elements and optimizing parameters such as the sintering process, a high emissivity of 0.89 (room temperature) and 0.95 (773K) at 3~5μm can be obtained. The material can be applied in industrial furnace energy saving, medical care, infrared heating, spacecraft thermal control, and improving thermoelectric conversion efficiency.

[0022] The present invention realizes high infrared radiation performance on CaTiO3-based oxide materials for the first time, and the preparation method of the present invention is simple and low in cost, and the prepared CaTiO3-based ceramic sheet has high infrared emissivity.

[0023] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 XRD patterns of the bulk prepared in Comparative Example, Example 1, Example 2, Example 3 and Example 4;

[0025] Figure 2 The EPMA backscatter images of the bulk prepared in Example 3 and Example 4, where (a) is the Ca 0.8 La 0.2 TiO 3-δ2 EPMA backscatter image; (b) Ca under 1 μm condition 0.8 La 0.2 TiO 3-δ2 EPMA backscatter diagram; (c) is the point scan result of the element type and content at the marked position in (b); (d) is the Ca under 10μm condition 0.8 Ce 0.2 TiO 3-δ2 EPMA backscatter image; (e) Ca under 1 μm condition 0.8 Ce 0.2 TiO 3-δ2 EPMA backscatter diagram; (f) is the point scan result of the element type and content at the marked position in (e);

[0026] Figure 3 This is a graph showing the relationship between infrared emissivity and temperature in the wavelength range of 3-5 μm for the blocks prepared in the comparative example, example 1, example 2, example 3 and example 4. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Any other changes, modifications, substitutions, combinations, and simplifications made without violating the spirit and principle of the present invention should all be equivalent replacement methods and are included in the protection scope of the present invention. In addition, it should be understood that after reading the content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application, and all belong to the scope of protection of the present invention.

[0028] Reference to "embodiment" herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The term "embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or association with other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the various technical features mentioned in the embodiments can be combined in any way to form a corresponding implementable technical solution.

[0029] Unless otherwise defined, the technical terms used in this document have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms in this document is only for describing specific embodiments and is not intended to limit this application.

[0030] Unless otherwise specified in the present invention, the reagents, instruments, and equipment used are those commonly used by technicians in this field.

[0031] Example 1

[0032] This embodiment discloses a CaTiO3-based oxide high infrared radiation material, whose chemical formula is Ca 0.8 La 0.2 TiO3, the preparation method thereof comprises the following steps:

[0033] (1) Weigh 18.58 g of CaTiO3 (purity ≥ 99.5%) and add it to 30 ml of anhydrous ethanol. Stir the mixture with electromagnetic stirring for 5 min to obtain suspension A.

[0034] (2) Weigh 5.54 g of La2O3 (purity ≥ 99.99%) and add it to suspension A. Stir the mixture with electromagnetic stirring for 1 h to obtain suspension B.

[0035] (3) The suspension B was transferred into a drying oven, kept at 80°C for 2 h, and dried to obtain a mixed powder of CaTiO3 and La2O3.

[0036] (4) The mixed powder obtained above was pre-pressed and then moved into a muffle furnace for sintering at a heating rate of 5°C / min and kept at 1450°C for 6 hours to obtain Ca 0.8 La 0.2 TiO3 based oxide high infrared radiation ceramic sheet.

[0037] Example 2

[0038] This embodiment discloses a CaTiO3-based oxide high infrared radiation material, whose chemical formula is Ca 0.8 La 0.2 TiO 3-δ1 , and its preparation method comprises the following steps:

[0039] (1) Weigh 18.58 g of CaTiO3 (purity ≥ 99.5%) and add it to 30 ml of anhydrous ethanol. Stir the mixture with electromagnetic stirring for 5 min to obtain suspension A.

[0040] (2) Weigh 5.54 g of La2O3 (purity ≥ 99.99%) and add it to suspension A. Stir the mixture with electromagnetic stirring for 1 h to obtain suspension B.

[0041] (3) The suspension B was transferred into a drying oven, kept at 80°C for 2 h, and dried to obtain a mixed powder of CaTiO3 and La2O3.

[0042] (4) The obtained mixed powder was pre-pressed into a shape and transferred into a crucible buried with carbon powder, and sintered in a muffle furnace at a heating rate of 5°C / min and kept at 1450°C for 6 hours to obtain Ca 0.8 La 0.2 TiO 3-δ1 Oxide-based high infrared radiation ceramics.

[0043] Example 3

[0044] This embodiment discloses a CaTiO3-based oxide high infrared radiation material, whose chemical formula is Ca 0.8 La 0.2 TiO 3-δ2 , and its preparation method comprises the following steps:

[0045] (1) Weigh 18.58 g of CaTiO3 (purity ≥ 99.5%) and add it to 30 ml of anhydrous ethanol. Stir the mixture with electromagnetic stirring for 5 min to obtain suspension A.

[0046] (2) Weigh 5.54 g of La2O3 (purity ≥ 99.99%) and add it to suspension A. Stir the mixture with electromagnetic stirring for 1 h to obtain suspension B.

[0047] (3) The suspension B was transferred into a drying oven, kept at 80°C for 2 h, and dried to obtain a mixed powder of CaTiO3 and La2O3.

[0048] (4) The obtained mixed powder was placed in a graphite mold and sintered in a vacuum hot pressing sintering furnace with a vacuum degree of 1 Pa and a pressure of 10 MPa, and kept at 1450 ° C for 3 h to obtain Ca 0.8 La 0.2 TiO 3-δ2 Oxide-based high infrared radiation ceramics.

[0049] Example 4

[0050] This embodiment discloses a CaTiO3-based oxide high infrared radiation material, whose chemical formula is Ca 0.8 Ce 0.2 TiO 3-δ2 , and its preparation method comprises the following steps:

[0051] (1) Weigh 18.58 g of CaTiO3 (purity ≥ 99.5%) and add it to 30 ml of anhydrous ethanol. Stir the mixture with electromagnetic stirring for 5 min to obtain suspension A.

[0052] (2) Weigh 5.86 g of CeO2 (purity ≥ 99.95%) and add it to suspension A. Stir with electromagnetic stirring for 1 h to obtain suspension B.

[0053] (3) The suspension B was transferred into a drying oven, kept at 80°C for 2 h, and dried to obtain a mixed powder of CaTiO3 and CeO2.

[0054] (4) The obtained mixed powder was placed in a graphite mold and sintered in a vacuum hot pressing sintering furnace with a vacuum degree of 1 Pa and a pressure of 10 MPa, and kept at 1450 ° C for 3 h to obtain Ca 0.8 Ce 0.2 TiO 3-δ2 Oxide-based high infrared radiation ceramics.

[0055] Comparative Example

[0056] This comparative example discloses a CaTiO3-based oxide high infrared radiation material, whose chemical formula is CaTiO3, and whose preparation method is:

[0057] Weigh 18.58 g of CaTiO3 (purity ≥ 99.5%) powder, pre-press it into a mold and move it into a muffle furnace. The heating rate is 5°C / min and it is kept at 1450°C for 6 hours to obtain a CaTiO3-based oxide high infrared radiation ceramic sheet.

[0058] Figure 1 For comparative example CaTiO3, Example 1Ca0.8 La 0.2 TiO3, Example 2Ca 0.8 La 0.2 TiO 3-δ1 Example 3Ca 0.8 La 0.2 TiO 3-δ2 Example 4Ca 0.8 Ce 0.2 TiO 3-δ2 XRD pattern of Figure 1 It can be seen that Ca 0.8 La 0.2 TiO3、Ca 0.8 La 0.2 TiO 3-δ1 , Ca 0.8 La 0.2 TiO 3-δ2 With Ca 0.8 Ce 0.2 TiO 3-δ2 The main peak of the block corresponds to the PDF#97-007-4213 card of CaTiO3, and there is no obvious impurity peak.

[0059] Figure 2 Example 3Ca 0.8 La 0.2 TiO 3-δ2 Example 4Ca 0.8 Ce 0.2 TiO 3-δ2 The EPMA diagram of the material and the corresponding element point scan data were obtained. Figure 2 It can be seen that La or Ce elements are evenly distributed in the matrix without obvious precipitation.

[0060] Figure 3 For comparative example CaTiO3, Example 1Ca 0.8 La 0.2 TiO3, Example 2Ca 0.8 La 0.2 TiO 3-δ1 Example 3Ca 0.8 La 0.2 TiO 3-δ2 Example 4Ca 0.8 Ce 0.2 TiO 3-δ2 The relationship between infrared emissivity and temperature in the 3-5μm band. Figure 3 It can be seen that the doping of La and Ce can effectively improve the infrared emissivity of 3-5 μm. 0.8 La 0.2 TiO 3-δ1 Sample, Example 3Ca0.8 La 0.2 TiO 3-δ2 Sample and Example 4Ca 0.8 Ce 0.2 TiO 3-δ2 The emissivity of the samples at 303K is 0.898, 0.853 and 0.874, which are 28.8%, 22.3% and 25.3% higher than that of pure CaTiO3 (0.697@303K). 0.8 La 0.2 TiO 3-δ1 , Ca 0.8 La 0.2 TiO 3-δ With Ca 0.8 Ce 0.2 TiO 3-δ2 The emissivity of the samples are 0.974, 0.987 and 0.974, respectively, which are 15.4%, 16.9% and 15.4% higher than that of pure CaTiO3 (0.844).

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for preparing a CaTiO3-based oxide high infrared radiation material, characterized in that: The following steps are involved: (1) Add CaTiO3 into anhydrous ethanol and stir with electromagnetic stirring to obtain suspension A; (2) adding rare earth oxide to suspension A and stirring with electromagnetic field to obtain suspension B; (3) The suspension B is transferred into a drying oven and dried to obtain a mixed powder of CaTiO3 and rare earth oxides; (4) pre-pressing the mixed powder, sintering and heat-insulating to obtain a CaTiO3-based oxide high infrared radiation material; The specific chemical formula of the CaTiO3-based oxide high infrared radiation material is: Ca 1-x RE x TiO 3-δ , where RE is a rare earth element, 0<x≤0.5, 0<δ≤0.5; The rare earth element is one of La and Ce; The specific operation of step (4) is as follows: pre-pressing the mixed powder into a crucible buried with carbon powder, sintering and heat preservation in a muffle furnace, the sintering heating rate is 5°C / min, and after sintering, the temperature is kept at 1400-1500°C for 6h to obtain Ca 1- x RE x TiO 3-δ Base oxide high infrared radiation materials; Alternatively, the specific operation of step (4) is as follows: placing the mixed powder into a graphite mold, sintering and heat preservation in a vacuum hot pressing sintering furnace, the vacuum degree is ≤1Pa, the pressure is 1~20MPa, and after sintering, the temperature is kept at 1400~1500℃ for 3h to obtain Ca 1- x RE x TiO 3-δ Oxide-based high infrared radiation materials.

2. The method for preparing a CaTiO3-based oxide high infrared radiation material according to claim 1, characterized in that: The electromagnetic stirring time in step (1) is 5 to 10 minutes; the electromagnetic stirring time in step (2) is 1 to 2 hours.

3. The method for preparing a CaTiO3-based oxide high infrared radiation material according to claim 1, characterized in that: In step (3), drying is performed at 80°C for 1 to 2 hours.

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