A flaky ceria polishing powder, a preparation method thereof and a polishing liquid

Abstract

The application relates to a flaky cerium dioxide polishing powder and a preparation method and a polishing liquid thereof. The preparation method comprises the following steps: mixing a cerium source and oxalic acid in a waterless solvent to obtain a mixed solution; placing the mixed solution in a sealed container to perform hydrothermal reaction to obtain a precursor; and performing calcination on the precursor to obtain the flaky cerium dioxide polishing powder. The application takes the cerium source and the oxalic acid as raw materials, controls the molar ratio of Ce and the oxalic acid in a waterless solvent system, and realizes the morphology control of the precursor through the hydrothermal reaction, so that the uniform flaky cerium dioxide polishing powder is obtained after calcination. In the polishing process, the flaky cerium dioxide polishing powder is beneficial to increasing the polishing and etching amount and improving the polishing rate, and based on the unique mixed valence of the cerium dioxide, the polishing precision is high, and the surface roughness is small under the joint action of the mechanical and chemical effects.

Description

Technical Field

[0001] This invention relates to the field of chemical mechanical polishing technology, specifically to polishing powder, and more particularly to a flake-shaped cerium dioxide polishing powder, its preparation method, and polishing liquid. Background Technology

[0002] Chemical mechanical polishing (CMP) achieves ultra-smooth and low-damage surfaces through the synergistic effect of mechanical wear and chemical corrosion. The CMP process depends on the choice of abrasive and the control of the chemical environment. Cerium dioxide, with its unique mixed valence state and excellent physicochemical properties, is widely used in CMP. When cerium dioxide polishing powder is applied to silicon wafer polishing, the agglomerated cerium dioxide particles are dispersed under the combined mechanical and chemical action, generating more defects, oxygen vacancies, and free electrons. 4+ Reduced to Ce 3+ Ce 3+ It reacts chemically with the Si-O-Si or Si-OH bonds on the SiO2 surface to form Ce-O-Si bonds. The formation and breaking of these bonds enable efficient polishing of CeO2.

[0003] CN103130262A discloses a method for preparing low-polish cerium oxide polishing powder. First, a cerium nitrate solution is added to a reaction vessel. Under stirring conditions, a certain amount of cerium oxalate is added. Then, the material in the reaction vessel is heated to maintain a temperature of 45-60°C. At this temperature, an oxalic acid solution is added. After the oxalic acid solution is completely added, stirring continues for 20-45 minutes. Then, stirring is stopped, and the cerium oxalate precursor is allowed to precipitate and stand for 15-30 minutes. It is then washed with water until the pH value reaches 6.5-7.0. The precipitate is then dried and filtered to form loose granular cerium oxalate material. Next, the dried and filtered cerium oxalate material is kept at a constant temperature, cooled, and then sieved to remove impurities, yielding cerium oxide polishing powder with an average particle size of 7-10 μm and a maximum particle size controlled within 30 μm.

[0004] CN120964869A discloses the preparation of highly uniform cerium oxide abrasives and their application in chemical mechanical polishing slurries. The method uses cerium nitrate or cerium oxalate as the cerium source, supplemented by cationic or nonionic surfactants as structure directing agents. In a mixed solvent system composed of water and isopropanol or water and diethylene glycol in a specific volume ratio, the particle size and morphology are controlled by a solvothermal reaction. After the reaction product is cleaned, dried and calcined at high temperature, spherical cerium oxide nanoparticles with high particle size concentration, moderate surface roughness and good dispersibility are obtained. The cerium oxide powder is added to deionized water, and while stirring, a dispersant and amino acids are added sequentially. After stirring evenly and adjusting the volume, a pH adjuster is added to make the solution weakly acidic, thus obtaining a chemical mechanical polishing slurry.

[0005] CN118929731A discloses a method for preparing cerium oxide powder polishing material. Using cerium nitrate hexahydrate as raw material, spherical cerium nitrate hexahydrate particles are first prepared by anti-solvent precipitation. Then, under the induction of a pulsed electric field, they are heated and decomposed to generate cerium oxide powder. Finally, calcination at 1500℃ yields a high-performance cerium oxide powder polishing material with uniform particle size distribution, particle diameter of 1μm~3μm, and cubic structure of nano-sized particles with obvious directional crystallization orientation.

[0006] Therefore, it is of great significance to provide a cerium dioxide polishing powder with stable preparation process, high polishing rate and good polishing effect. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a flake-shaped cerium dioxide polishing powder, its preparation method, and polishing solution. This invention uses cerium source and oxalic acid as raw materials. In an anhydrous solvent system, by adjusting the molar ratio of Ce to oxalic acid and coordinating with a hydrothermal reaction, the morphology of the precursor is controlled. After calcination, a uniform flake-shaped cerium dioxide polishing powder is obtained. During the polishing process, this powder is beneficial for increasing the erosion amount and improving the polishing rate. Furthermore, based on the unique mixed valence state of cerium dioxide, under the combined action of mechanical and chemical processes, the polishing precision is high and the surface roughness is low.

[0008] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing flake-shaped cerium dioxide polishing powder, the method comprising: A cerium source and oxalic acid are mixed in an anhydrous solvent to obtain a mixed solution; the mixed solution is placed in a sealed container and subjected to a hydrothermal reaction to obtain a precursor; the precursor is calcined to obtain the flake-shaped cerium dioxide polishing powder; the molar ratio of Ce to oxalic acid in the cerium source is 1:(2.2~2.8).

[0009] This invention uses cerium source and oxalic acid as raw materials. In an anhydrous solvent system, by controlling the molar ratio of Ce to oxalic acid and coordinating with a hydrothermal reaction, the morphology of the precursor is controlled. After calcination, uniform flake-shaped cerium dioxide polishing powder is obtained. Compared with conventional granular or spherical cerium dioxide polishing powder, the flake-shaped cerium dioxide polishing powder provided by this invention has more sharp edges on its surface. During the polishing process, this is beneficial to increase the amount of erosion and improve the polishing rate. Furthermore, based on the unique mixed valence state of cerium dioxide, under the combined action of mechanical and chemical processes, the polishing precision is high and the surface roughness is small.

[0010] Preferably, the concentration of Ce in the mixed solution is 20 g / L to 40 g / L.

[0011] Preferably, the cerium source includes any one or a combination of at least two of cerium nitrate, cerium chloride, or cerium acetate.

[0012] Preferably, the anhydrous solvent includes anhydrous ethanol.

[0013] Preferably, the sealed container includes a hydrothermal reactor.

[0014] Preferably, the temperature of the hydrothermal reaction is 150℃~170℃.

[0015] Preferably, the hydrothermal reaction time is 10h to 15h.

[0016] Preferably, the heating rate of the hydrothermal reaction is 4℃ / min to 6℃ / min.

[0017] Preferably, the calcination temperature is 400℃~600℃.

[0018] Preferably, the roasting time is 3h to 5h.

[0019] Preferably, the heating rate of the calcination is 4℃ / min to 6℃ / min.

[0020] Preferably, the preparation method further includes cleaning and drying the precursor after the hydrothermal reaction is completed and before calcination.

[0021] Preferably, the cleaning includes ultrasonic washing and / or centrifugal washing.

[0022] Preferably, the drying temperature is 70℃~90℃.

[0023] Preferably, the preparation method further includes grinding the precursor and the flake cerium dioxide polishing powder respectively.

[0024] In a second aspect, the present invention provides a flake-shaped cerium dioxide polishing powder, which is prepared by the preparation method described in the first aspect.

[0025] Thirdly, the present invention provides a polishing liquid comprising flake cerium dioxide polishing powder as described in the second aspect.

[0026] Compared with the prior art, the present invention has the following beneficial effects: (1) In this invention, cerium source and oxalic acid are used as raw materials. In an anhydrous solvent system, by adjusting the molar ratio of Ce to oxalic acid and cooperating with hydrothermal reaction, the morphology of the precursor is controlled. After calcination, uniform flake cerium dioxide polishing powder is obtained.

[0027] (2) The flake cerium dioxide polishing powder provided by the present invention has more sharp edges and corners on its surface, which is beneficial to increase the amount of erosion and improve the polishing rate during the polishing process. Moreover, based on the unique mixed valence state of cerium dioxide, under the combined action of mechanical and chemical processes, the polishing precision is high and the surface roughness is small. Attached Figure Description

[0028] Figure 1 This is the XRD pattern of the polished sheet-like cerium dioxide obtained in Example 1.

[0029] Figure 2 This is a SEM image of the polished sheet-like cerium dioxide obtained in Example 1.

[0030] Figure 3 This is a SEM image of the polished sheet-like cerium dioxide obtained in Example 2.

[0031] Figure 4 This is a SEM image of the polished sheet-like cerium dioxide obtained in Example 3.

[0032] Figure 5 This is a SEM image of the polished sheet-like cerium dioxide obtained in Example 4.

[0033] Figure 6 This is a SEM image of the polished sheet-like cerium dioxide prepared in Comparative Example 1. Detailed Implementation

[0034] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0035] The "range" disclosed in this invention can be defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the specific range. This type of range definition can include or exclude endpoints; any endpoint can be independently included or excluded, and they can be arbitrarily combined, meaning any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for specific parameters, it is understood that ranges of 60~110 and 80~120 are also expected. Furthermore, if minimum range values ​​1 and 2 are listed, and maximum range values ​​3, 4, and 5 are also listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this invention, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0" and "5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is described as an integer ≥2, it is equivalent to listing integers such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For instance, when a parameter is described as an integer selected from "2~10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0036] In this invention, "a combination of at least two" refers to a quantity greater than or equal to two, unless otherwise specified. For example, "any combination of one or at least two" means one or more or more items. It can be understood that when referring to "a combination of at least two," it refers to any suitable combination of multiple items, that is, a combination of "at least two" items carried out in a manner that does not conflict with and enables the implementation of this invention.

[0037] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0038] The term "embodiment" as used in this invention means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment or implementation of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this invention can be combined with other embodiments.

[0039] Those skilled in the art will understand that the order in which the steps are written in the methods of the various embodiments does not imply a strict execution order. The detailed execution order of each step should be determined by its function and possible internal logic. Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, but are preferably performed sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), meaning that step (c) can be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0040] In this invention, open-ended technical features or solutions described using terms such as "comprising" do not exclude additional members beyond those listed unless otherwise specified. They can be considered as providing both closed-ended features or solutions comprised of the listed members and open-ended features or solutions that include additional members beyond the listed members. For example, A includes a1, a2, and a3. Unless otherwise specified, it may also include other members or exclude additional members. This can be considered as providing both technical features or solutions where "A is composed of a1, a2, and a3" or "A is selected from a1, a2, and a3," and technical features or solutions where "A includes not only a1, a2, and a3, but also other members."

[0041] In this invention, unless otherwise specified, the features or solutions corresponding to "and / or" include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. For example, "A and / or B" represents a group consisting of A, B, and "a combination of A and B". "Containing A and / or B" can mean "containing A, containing B, and containing A and B", or "containing A, containing B, or containing A and B", and can be appropriately understood according to the context.

[0042] In this invention, the terms "first aspect," "second aspect," "third aspect," "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on the quantity.

[0043] In this invention, "optional" means that something is optional, that is, it refers to either "with" or "without". If there are multiple "optional" options in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, then each "optional" option is independent.

[0044] In this invention, unless otherwise specified, it is assumed that the experiments are conducted at room temperature or a temperature conventionally set in the art. "Room temperature" generally refers to 4°C to 35°C, and may refer to 20°C ± 5°C. In some embodiments of this invention, room temperature refers to 20°C to 30°C.

[0045] In one specific embodiment, the present invention provides a method for preparing flake-shaped cerium dioxide polishing powder, the method comprising: A cerium source and oxalic acid are mixed in an anhydrous solvent to obtain a mixed solution; the mixed solution is placed in a sealed container and subjected to a hydrothermal reaction to obtain a precursor; the precursor is calcined to obtain the flake-shaped cerium dioxide polishing powder; the molar ratio of Ce to oxalic acid in the cerium source is 1:(2.2~2.8), for example, it can be 1:2.2, 1:2.3, 1:2.4, 1:2.5, 1:2.6, 1:2.7 or 1:2.8.

[0046] This invention uses cerium source and oxalic acid as raw materials. In an anhydrous solvent system, by controlling the molar ratio of Ce to oxalic acid and coordinating with a hydrothermal reaction, the morphology of the precursor is controlled. After calcination, uniform flake-shaped cerium dioxide polishing powder is obtained. Compared with conventional granular or spherical cerium dioxide polishing powder, the flake-shaped cerium dioxide polishing powder provided by this invention has more sharp edges on its surface. During the polishing process, this is beneficial to increase the amount of erosion and improve the polishing rate. Furthermore, based on the unique mixed valence state of cerium dioxide, under the combined action of mechanical and chemical processes, the polishing precision is high and the surface roughness is small.

[0047] In some embodiments, the method of mixing the cerium source and oxalic acid in an anhydrous solvent includes: first dissolving the cerium source in an anhydrous solvent, and then adding oxalic acid to obtain the mixed solution.

[0048] In some embodiments, the concentration of Ce in the mixed solution is 20 g / L to 40 g / L, for example, it can be 20 g / L, 25 g / L, 30 g / L, 35 g / L or 40 g / L.

[0049] In some embodiments, the cerium source includes any one or a combination of at least two of cerium nitrate, cerium chloride, or cerium acetate.

[0050] In some embodiments, the anhydrous solvent includes anhydrous ethanol.

[0051] In some embodiments, the sealed container includes a hydrothermal reactor. The lining of the hydrothermal reactor may be made of, for example, polytetrafluoroethylene (PTFE).

[0052] In some embodiments, the temperature of the hydrothermal reaction is 150°C to 170°C, for example, it can be 150°C, 155°C, 160°C, 165°C or 170°C.

[0053] In some embodiments, the hydrothermal reaction time is 10h to 15h, for example, 10h, 11h, 12h, 13h, 14h or 15h.

[0054] In some embodiments, the heating rate of the hydrothermal reaction is 4°C / min to 6°C / min, for example, it can be 4°C / min, 4.5°C / min, 5°C / min, 5.5°C / min or 6°C / min.

[0055] In some embodiments, the calcination temperature is 400°C to 600°C, for example, 400°C, 450°C, 500°C, 550°C or 600°C.

[0056] In some embodiments, the calcination time is 3h to 5h, for example, it can be 3h, 3.5h, 4h, 4.5h or 5h.

[0057] In some embodiments, the heating rate of the calcination is 4°C / min to 6°C / min, for example, it can be 4°C / min, 4.5°C / min, 5°C / min, 5.5°C / min or 6°C / min.

[0058] In some embodiments, the preparation method further includes cleaning and drying the precursor after the hydrothermal reaction is completed and before calcination.

[0059] In some embodiments, the cleaning includes ultrasonic washing and / or centrifugal washing. The cleaning can be performed sequentially using deionized water and anhydrous ethanol, and the number of cleaning cycles is not particularly limited. For example, it is possible to first ultrasonically wash twice with deionized water, then ultrasonically wash once with anhydrous ethanol, and then centrifuge wash three times with anhydrous ethanol.

[0060] In some embodiments, the drying temperature is 70°C to 90°C, for example, 70°C, 75°C, 80°C, 85°C or 90°C.

[0061] In some embodiments, the preparation method further includes grinding the precursor and the flake-shaped cerium dioxide polishing powder separately.

[0062] In another specific embodiment, the present invention provides a flake-shaped cerium dioxide polishing powder, which is prepared by the preparation method described in one of the aforementioned specific embodiments.

[0063] In yet another embodiment, the present invention provides a polishing liquid comprising flake cerium dioxide polishing powder as described in another preceding embodiment.

[0064] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0065] Example 1 This embodiment provides a method for preparing flake-shaped cerium dioxide polishing powder, the preparation method comprising: Cerium nitrate was dissolved in anhydrous ethanol, and oxalic acid was added to obtain a mixed solution in which the molar ratio of Ce to oxalic acid was 1:2.8, and the concentration of Ce in the mixed solution was 33 g / L. The mixed solution was placed in a polytetrafluoroethylene-lined hydrothermal reactor and heated to 160°C at a heating rate of 5°C / min for 12 h. After the hydrothermal reaction, the supernatant was discarded, and the precipitate was ultrasonically washed twice with deionized water, ultrasonically washed once with anhydrous ethanol, and then centrifuged and washed three times with anhydrous ethanol. The precipitate was dried at 80°C and ground to obtain the precursor. The obtained precursor was heated to 500°C at a heating rate of 5°C / min, calcined for 4 h, and ground to obtain the flake-shaped cerium dioxide polishing powder.

[0066] like Figure 1 As shown, this embodiment prepared sheet-like cerium dioxide polishing powder with a thickness of nanometers and a width of micrometers. Its XRD pattern is shown in the figure. Figure 2 As shown.

[0067] Example 2 This embodiment provides a method for preparing flake-shaped cerium dioxide polishing powder, the preparation method comprising: Cerium nitrate was dissolved in anhydrous ethanol, and oxalic acid was added to obtain a mixed solution in which the molar ratio of Ce to oxalic acid was 1:2.6, and the concentration of Ce in the mixed solution was 20 g / L. The mixed solution was placed in a polytetrafluoroethylene-lined hydrothermal reactor and heated to 150°C at a heating rate of 4°C / min for 15 h. After the hydrothermal reaction, the supernatant was discarded, and the precipitate was ultrasonically washed twice with deionized water, ultrasonically washed once with anhydrous ethanol, and then centrifuged and washed three times with anhydrous ethanol. The precipitate was dried at 70°C and ground to obtain the precursor. The obtained precursor was heated to 400°C at a heating rate of 4°C / min, calcined for 5 h, and ground to obtain the flake-shaped cerium dioxide polishing powder.

[0068] like Figure 3 As shown, this embodiment prepares sheet-like cerium dioxide polishing powder with a thickness of nanometers and a width of micrometers.

[0069] Example 3 This embodiment provides a method for preparing flake-shaped cerium dioxide polishing powder, the preparation method comprising: Cerium chloride was dissolved in anhydrous ethanol, and oxalic acid was added to obtain a mixed solution, wherein the molar ratio of Ce to oxalic acid was 1:2.2, and the concentration of Ce in the mixed solution was 40 g / L. The mixed solution was placed in a polytetrafluoroethylene-lined hydrothermal reactor and heated to 170°C at a heating rate of 6°C / min for hydrothermal reaction for 10 h. After the hydrothermal reaction was completed, the supernatant was discarded, and the precipitate was ultrasonically washed three times with deionized water, then ultrasonically washed twice with anhydrous ethanol, and then centrifuged and washed three times with anhydrous ethanol. The precipitate was dried at 90°C and ground to obtain the precursor. The obtained precursor was heated to 600°C at a heating rate of 6°C / min, calcined for 3 h, and ground to obtain the flake-shaped cerium dioxide polishing powder.

[0070] like Figure 4 As shown, this embodiment prepares sheet-like cerium dioxide polishing powder with a thickness of nanometers and a width of micrometers.

[0071] Example 4 This embodiment provides a method for preparing flake-shaped cerium dioxide polishing powder. The preparation method is the same as in Example 1, except that the molar ratio of Ce to oxalic acid in cerium nitrate is 1:2.4.

[0072] like Figure 5 As shown, this embodiment prepares sheet-like cerium dioxide polishing powder with a thickness of nanometers and a width of micrometers.

[0073] Comparative Example 1 This comparative example provides a method for preparing cerium dioxide polishing powder. The preparation method is the same as in Example 1, except that the molar ratio of Ce to oxalic acid in cerium nitrate is 1:3.2.

[0074] like Figure 6 As shown, the spherical cerium dioxide polishing powder prepared in this comparative example could not be prepared as flake-shaped cerium dioxide polishing powder.

[0075] Comparative Example 2 This comparative example provides a method for preparing cerium dioxide polishing powder. The preparation method is the same as in Example 1, except that the solvent of the mixed solution is replaced by anhydrous ethanol instead of water and anhydrous ethanol in a volume ratio of 1:4.

[0076] Performance testing: The cerium dioxide polishing powders prepared in Examples 1 to 3 and Comparative Examples 1 to 2 were dispersed in water and thoroughly mixed to form a polishing liquid with a cerium dioxide polishing powder content of 0.2 wt%. The mixture was used for silicon wafer polishing, and the polishing rate and the surface roughness after polishing were tested. The test results are shown in Table 1.

[0077] Table 1 In summary, this invention uses cerium source and oxalic acid as raw materials. In an anhydrous solvent system, by adjusting the molar ratio of Ce to oxalic acid and coordinating with a hydrothermal reaction, the morphology of the precursor is controlled. After calcination, uniform flake-shaped cerium dioxide polishing powder is obtained.

[0078] Based on the test results of Example 1 and Comparative Example 1, when the molar ratio of Ce to oxalic acid is too small, i.e., the molar amount of oxalic acid is too high, such as Figure 6 As shown, spherical cerium dioxide polishing powder can be obtained, but flake-shaped cerium dioxide polishing powder cannot be obtained, and the polishing rate decreases significantly.

[0079] According to the test results of Example 1 and Comparative Example 2, when the anhydrous solvent is replaced with an aqueous solvent, it is still impossible to obtain flake-shaped cerium dioxide polishing powder, which is not conducive to improving the polishing rate.

[0080] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing flake-shaped cerium dioxide polishing powder, characterized in that, The preparation method includes: A cerium source and oxalic acid are mixed in an anhydrous solvent to obtain a mixed solution; the mixed solution is placed in a sealed container and subjected to a hydrothermal reaction to obtain a precursor; the precursor is calcined to obtain the flake-shaped cerium dioxide polishing powder. The molar ratio of Ce to oxalic acid in the cerium source is 1:(2.2~2.8).

2. The preparation method according to claim 1, characterized in that, The concentration of Ce in the mixed solution is 20 g / L to 40 g / L.

3. The preparation method according to claim 1 or 2, characterized in that, The cerium source includes any one or a combination of at least two of cerium nitrate, cerium chloride, or cerium acetate. And / or, the anhydrous solvent includes anhydrous ethanol; And / or, the sealed container includes a hydrothermal reactor.

4. The preparation method according to any one of claims 1 to 3, characterized in that, The temperature of the hydrothermal reaction is 150℃~170℃; And / or, the hydrothermal reaction time is 10h~15h; And / or, the heating rate of the hydrothermal reaction is 4℃ / min to 6℃ / min.

5. The preparation method according to any one of claims 1 to 4, characterized in that, The roasting temperature is 400℃~600℃; And / or, the calcination time is 3h~5h; And / or, the heating rate of the calcination is 4℃ / min to 6℃ / min.

6. The preparation method according to any one of claims 1 to 5, characterized in that, The preparation method further includes cleaning and drying the precursor after the hydrothermal reaction is completed and before calcination.

7. The preparation method according to claim 6, characterized in that, The cleaning includes ultrasonic washing and / or centrifugal washing; And / or, the drying temperature is 70℃~90℃.

8. The preparation method according to any one of claims 1 to 7, characterized in that, The preparation method further includes grinding the precursor and the flake-shaped cerium dioxide polishing powder respectively.

9. A flake-shaped cerium dioxide polishing powder, characterized in that, The flake-shaped cerium dioxide polishing powder is prepared by the preparation method according to any one of claims 1 to 8.

10. A polishing liquid, characterized in that, The polishing fluid includes the flake-shaped cerium dioxide polishing powder as described in claim 9.

Images