A production method for a large-sized nickel oxide planar target

Abstract

The present invention belongs to the technical field of target materials, and specifically relates to a production method of a large-sized nickel oxide planar target. The production method comprises the following steps: S1: Injecting a slurry containing nickel oxide into a mold, and drying to obtain a primary green body; S2: Performing degumming treatment on the primary green body and then pre-sintering it in an oxygen-free atmosphere; S3: Crushing the pre-sintered primary green body, sieving it to obtain powder, adding a binder, mixing evenly, granulating, sieving, and cold isostatically pressing to form a secondary green body; S4: Heating and sintering the secondary green body to obtain a large-sized nickel oxide planar target; The large-sized nickel oxide planar target prepared by the present invention has a lower resistivity and a higher relative density.

Description

Technical Field

[0001] The present invention belongs to the technical field of target materials, and particularly relates to a production method of a large-size nickel oxide planar target. Background Art

[0002] Currently, perovskite solar cells are one of the important directions in the future photovoltaic industry. Due to their high theoretical conversion efficiency and the ability to be stacked with crystalline silicon solar cells, they have become a research hotspot in the photovoltaic field. Perovskite solar cells usually consist of multiple functional layers, among which the hole transport layer plays a crucial role. Nickel oxide thin films have become an ideal material for preparing the hole transport layer due to their good electrical properties, chemical stability, and compatibility with perovskite materials.

[0003] Magnetron sputtering is an efficient physical vapor deposition technology applied to thin film preparation and surface modification. By this method, the desired thin film can be accurately deposited on the substrate using a nickel oxide target. The quality of the sputtering target plays a crucial role in the quality of the thin film. To achieve the desired thin film characteristics, factors such as the density and grain size of the target must be precisely adjusted.

[0004] The Chinese patent application document with the publication number CN116768606A discloses a preparation method of a composite nickel oxide magnesium target. This application document uses NiO powder and MgO powder as raw materials to prepare a composite nickel oxide magnesium target, mainly adjusting the processes such as ball milling and mold loading in the preparation process of the target. The preparation method is simple, and the composite nickel oxide magnesium target is relatively uniform; however, the highest relative density of the prepared target only reaches 98.5%. At the same time, this method dopes a relatively high amount of magnesium element in the target, which is likely to cause lattice expansion and may lead to target cracking. Summary of the Invention

[0005] Existing nickel oxide targets have problems such as low density and easy cracking; to solve this problem, the present invention provides a production method of a large-size nickel oxide planar target.

[0006] To achieve the purpose of the present invention, the following technical solutions are adopted in the present invention:

[0007] The present invention provides a production method of a large-size nickel oxide planar target, including the following steps:

[0008] S1: Inject the slurry containing nickel oxide into a mold, dry it to obtain a primary green body;

[0009] S2: After degumming the primary green body, perform pre-sintering in an oxygen-free atmosphere;

[0010] S3: Crush the pre-sintered primary green body, screen it to obtain powder, add a binder, mix evenly, granulate, screen, and perform cold isostatic pressing to form a secondary green body;

[0011] S4: Heat the secondary green body to sinter it, obtaining a large-sized nickel oxide planar target.

[0012] Preferably, in step S1, the method for preparing the slurry containing nickel oxide includes the following steps:

[0013] (1) Mix the organic monomer, crosslinking agent, and water evenly, and adjust the pH to 8 - 10 to obtain mixture A;

[0014] (2) Mix nickel oxide, sintering aid, additive, and water evenly to obtain mixture B;

[0015] (3) Mix mixture A and mixture B evenly to obtain a premix, add an initiator and a catalyst and mix evenly to obtain the slurry containing nickel oxide.

[0016] Preferably, the mass ratio of the organic monomer to nickel oxide is (0.015 - 0.04)∶1.

[0017] By adopting the above technical solution, at this ratio, the gel forms a uniform network structure around the nickel oxide, tightly fixing the nickel oxide together during the polymerization process, enabling the green body to have good shape retention and reducing damage to the green body during demolding.

[0018] Preferably, in step (1), the mass ratio of the organic monomer to the crosslinking agent is 1∶(0.1 - 0.2).

[0019] By adopting the above technical solution, at this ratio, the three-dimensional network structure formed by the crosslinking of the organic monomer can maintain the size and shape of the large-sized target, making the green body not easily deformed during demolding, drying, and subsequent processing.

[0020] Preferably, in step (1), the organic monomer is one of methacrylamide and ethyl methacrylate, and the crosslinking agent is N,N'-methylenebisacrylamide.

[0021] Preferably, in step (2), the mass ratio of nickel oxide to the sintering aid is 1∶(0.01 - 0.03).

[0022] Preferably, in step (2), the sintering aid is composed of cadmium oxide and samarium oxide in a mass ratio of (2 - 4)∶1.

[0023] By adopting the above technical solution, at this ratio, the sintering aid can form a liquid phase, reduce the sintering temperature, increase the diffusion and sintering rates, and contribute to densification at a relatively low temperature.

[0024] Preferably, in step (2), the dosage of the additive is 0.5% - 1.5% of the mass of nickel oxide.

[0025] Preferably, in the step (2), the additive is composed of polyvinylpyrrolidone, diethylene glycol amine and carboxymethyl cellulose in a mass ratio of (5-8):1:(2-4).

[0026] By adopting the above technical solution, the dispersion stability of the three components for nickel oxide reaches the optimal level at this ratio, effectively preventing the sedimentation and agglomeration of nickel oxide.

[0027] Preferably, in the step (2), the uniform mixing includes ultrasonic dispersion and ball milling, specifically as follows:

[0028] The time of ultrasonic dispersion is 20-30 min.

[0029] By adopting the above technical solution, within this time range, ultrasonic dispersion can fully play its role, effectively breaking the agglomeration between nickel oxides and making nickel oxides uniformly dispersed.

[0030] The speed of ball milling is 400-800 rpm, and the time of ball milling is 10-15 h.

[0031] By adopting the above technical solution, within this time range, nickel oxide is sufficiently crushed and refined, and the particle size distribution of nickel oxide is uniform, with good dispersion effect.

[0032] Preferably, in the step (3), the initiator is benzoyl peroxide; the catalyst is N,N-dimethylacetamide.

[0033] Preferably, in the step S1, the specific steps of drying are as follows: drying in a vacuum oven at 40-50 °C for 5-8 h, demolding, and then continuing to dry in a vacuum oven at 70-80 °C for 8-12 h.

[0034] Preferably, in the step S2, the specific steps of degumming treatment are as follows: sintering at atmospheric pressure at 500-600 °C, with a heating rate of 1-2 °C / min, a holding time of 5-8 h, and cooling to room temperature with the furnace.

[0035] Preferably, in the step S2, the specific steps of pre-sintering are as follows: subjecting the primary green body to atmospheric pressure sintering at a temperature of 850-900 °C, with a heating rate of 3-5 °C / min, a holding time of 3-5 h, and cooling to room temperature with the furnace.

[0036] Preferably, in the step S3, the binder is selected from one of polyvinyl alcohol and polyethylene glycol.

[0037] Preferably, in the step S4, the temperature-raising sintering includes a first-stage sintering and a second-stage sintering, which are specifically as follows: Neon is introduced during the first-stage sintering. The sintering temperature is 500 - 800 °C, the heating rate is 0.5 - 1.5 °C / min, the heat preservation duration is 3 - 8 h, and the sintering pressure is 20 - 80 Pa. Oxygen is introduced during the second-stage sintering. The sintering temperature is 1250 - 1400 °C, the heating rate is 3 - 5 °C / min, the sintering time is 8 - 20 h, the sintering pressure is 200 - 500 Pa, and the heat preservation duration is 2 - 8 h. The heating rate from the first-stage sintering temperature to the second-stage sintering temperature is 2 °C / min.

[0038] By adopting the above technical means, introducing oxygen during the second-stage sintering can enable the grains to grow more uniformly, reduce the difference in grain size, and make the structure of the target more uniform and dense. At the same time, it can promote the uniform growth of grains and reduce lattice defects, making the electron transport channels inside the target smoother, thereby improving the conductivity.

[0039] In summary, the beneficial effects of the present invention are as follows:

[0040] (1) The initial use of gel injection molding in the present invention can make the raw material powder uniformly disperse in the gel system to form a green body with a relatively uniform internal structure. Using isostatic pressing as the secondary forming method can apply isotropic pressure to the green body, enabling the green body to be uniformly compacted in all directions, which can effectively improve the density and density uniformity of the green body. The densification rate of the green body after pre-sintering is faster, and its grain size is also more uniform.

[0041] (2) The present invention modifies the surface of nickel oxide through polyvinylpyrrolidone, diethanolamine, and carboxymethyl cellulose to generate an isolation layer on the surface of nickel oxide particles, which is beneficial to improving the uniformity of the internal structure of the target. Using steric hindrance to avoid local density differences and defects caused by powder agglomeration and enhance the performance stability of the target.

[0042] (3) The present invention uses nickel oxide as the main component and cadmium oxide and samarium oxide as sintering aids, which can form a small amount of liquid phase during the sintering stage, promote particle rearrangement and pore filling, reduce defects such as pores and cracks, and improve the density and hardness of the target. Cadmium oxide can increase the carrier mobility after coating adjustment, reduce the resistance, and improve the electrical properties.

[0043] (4) The finished product of the large-size nickel oxide planar target prepared by the present invention has a single-piece length of 500 - 1000 mm, a width of 100 - 200 mm, and a thickness of 5 - 10 mm, and has a low resistivity and a high relative density. Detailed implementation manners

[0044] The technical solutions of the present invention will be explained in detail below with reference to several representative embodiments of the present invention.

[0045] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods. Unless otherwise specified, the materials, reagents, etc. used in the following examples can all be obtained from commercial channels.

[0046] The average particle size of the nickel oxide used in the present invention is 250 nm, and the purity is ≥99.99%;

[0047] The average particle size of the cadmium oxide used in the present invention is 200 nm, and the purity is ≥99.99%;

[0048] The average particle size of the samarium oxide used in the present invention is 200 nm, and the purity is ≥99.99%.

[0049] Example 1

[0050] A production method of a large-size nickel oxide planar target in this example is as follows:

[0051] S1: Inject the slurry containing nickel oxide into the mold, dry it in a vacuum oven at 40°C for 6 h, demold, and continue to dry it in a vacuum oven at 70°C for 8 h to obtain a primary green body;

[0052] S2: Under a neon atmosphere, sinter the primary green body at 550°C under normal pressure, with a heating rate of 1°C / min and a holding time of 8 h, and cool it to room temperature with the furnace to obtain a primary green body after degumming treatment; under a neon atmosphere, sinter the primary green body after degumming treatment at normal pressure, with a temperature of 900°C, a heating rate of 4°C / min, a holding time of 5 h, and cool it to room temperature with the furnace to obtain a primary green body after pre-sintering;

[0053] S3: Crush the primary green body after pre-sintering, pass it through a 100-mesh sieve to obtain powder, add 10% by mass of polyvinyl alcohol, ball mill it in a ball mill at a speed of 400 rpm for 6 h, granulate it using a spray dryer, pass it through a 150-mesh sieve, and press it into shape using a cold isostatic press at 200 MPa to obtain a secondary green body;

[0054] S4: Transfer the secondary green body to a sintering furnace for sintering. During the first-stage sintering process, neon is introduced, the sintering temperature is 800°C, the heating rate is 1.5°C / min, the holding time is 4 h, and the sintering pressure is 80 Pa; the heating rate from the first-stage sintering temperature to the second-stage sintering temperature is 2°C / min; during the second-stage sintering process, oxygen is introduced, the sintering temperature is 1250°C, the heating rate is 5°C / min, the sintering time is 20 h, the sintering pressure is 500 Pa, and the holding time is 5 h; cool it to room temperature with the furnace to obtain a large-size nickel oxide planar target.

[0055] The preparation method of the slurry containing nickel oxide in this embodiment is as follows:

[0056] (1) Mix 3 g of methylacrylamide, 0.3 g of N,N'-methylenebisacrylamide with 90 g of water, stir for 30 min, and adjust the pH to 8 to obtain mixture A;

[0057] (2) Mix 100 g of nickel oxide, 1.5 g of cadmium oxide, 0.5 g of samarium oxide, 1 g of polyvinylpyrrolidone, 0.125 g of diethanolamine, 0.375 g of hydroxymethylcellulose with 60 g of water, ultrasonically disperse for 25 min, transfer to a ball mill and ball mill at a speed of 600 rpm for 12 h to obtain mixture B;

[0058] (3) Mix mixture A and mixture B, ultrasonically disperse for 30 min to obtain a premix, add 0.5 g of benzoyl peroxide and 0.08 g of N,N-dimethylacetamide and ultrasonically disperse for 10 min to obtain the slurry containing nickel oxide.

[0059] Example 2

[0060] The production method of a large-size nickel oxide planar target in this embodiment is as follows:

[0061] S1: Inject the slurry containing nickel oxide into a mold, dry it in a vacuum oven at 40°C for 8 h, demold, and continue to dry it in a vacuum oven at 80°C for 12 h to obtain a primary green body;

[0062] S2: Under a neon atmosphere, sinter the primary green body at 600°C under normal pressure, with a heating rate of 1.5°C / min and a holding time of 8 h, and cool it to room temperature with the furnace to obtain the primary green body after degumming treatment; Under a neon atmosphere, sinter the primary green body after degumming treatment at normal pressure, with a temperature of 850°C, a heating rate of 3°C / min, and a holding time of 4 h, and cool it to room temperature with the furnace to obtain the primary green body after pre-sintering;

[0063] S3: Crush the primary green body after pre-sintering, pass it through a 100-mesh sieve to obtain powder, add polyvinyl alcohol and ball mill it in a ball mill at a speed of 400 rpm for 6 h, granulate it using a spray dryer, pass it through a 150-mesh sieve, and press it into shape at 200 MPa using a cold isostatic press to obtain a secondary green body;

[0064] S4: Transfer the secondary green body to a sintering furnace for sintering. Neon gas is introduced during the first-stage sintering process. The sintering temperature is 500 °C, the heating rate is 1 °C / min, the holding time is 6 h, and the sintering pressure is 20 Pa. The heating rate from the first-stage sintering temperature to the second-stage sintering temperature is 2 °C / min. Oxygen is introduced during the second-stage sintering process. The sintering temperature is 1300 °C, the heating rate is 3 °C / min, the sintering time is 10 h, the sintering pressure is 300 Pa, the holding time is 2 h, and it is cooled to room temperature with the furnace to obtain a large-sized nickel oxide planar target.

[0065] The preparation method of the slurry containing nickel oxide in this embodiment is as follows:

[0066] (1) Mix 1.5 g of methylacrylamide, 0.3 g of N,N'-methylenebisacrylamide with 90 g of water, stir for 30 min, and adjust the pH to 9 to obtain a mixed solution A;

[0067] (2) Mix 100 g of nickel oxide, 2 g of cadmium oxide, 1 g of samarium oxide, 0.5 g of polyvinylpyrrolidone, 0.1 g of diethanolamine, 0.2 g of carboxymethyl cellulose with 60 g of water, ultrasonically disperse for 30 min, transfer to a ball mill and ball mill at a speed of 800 rpm for 15 h to obtain a mixed solution B;

[0068] (3) Mix the mixed solution A and the mixed solution B, ultrasonically disperse for 30 min to obtain a premix, add 0.5 g of benzoyl peroxide and 0.08 g of N,N-dimethylacetamide and ultrasonically disperse for 10 min to obtain a slurry containing nickel oxide.

[0069] Example 3

[0070] The production method of a large-sized nickel oxide planar target in this embodiment is as follows:

[0071] S1: Inject the slurry containing nickel oxide into a mold, dry it in a vacuum oven at 45 °C for 5 h, demold, and continue to dry it in a vacuum oven at 75 °C for 12 h to obtain a primary green body;

[0072] S2: Under a neon gas atmosphere, sinter the primary green body at 500 °C under normal pressure, with a heating rate of 2 °C / min and a holding time of 5 h, and cool it to room temperature with the furnace to obtain a primary green body after degumming treatment; Under a neon gas atmosphere, sinter the primary green body after degumming treatment at a temperature of 880 °C, with a heating rate of 3.5 °C / min and a holding time of 3 h, and cool it to room temperature with the furnace to obtain a pre-sintered primary green body;

[0073] S3: Crush the pre-sintered green body, sieve it through a 100-mesh sieve to obtain powder, add polyethylene glycol, ball mill it in a ball mill at a speed of 400 rpm for 6 h, granulate it using a spray dryer, sieve it through a 150-mesh sieve, and use a cold isostatic press to press and form it at 200 MPa to obtain a secondary green body;

[0074] S4: Transfer the secondary green body to a sintering furnace for sintering. Neon is introduced during the first-stage sintering process. The sintering temperature is 600 °C, the heating rate is 0.5 °C / min, the holding time is 3 h, and the sintering pressure is 50 Pa. The heating rate from the first-stage sintering temperature to the second-stage sintering temperature is 2 °C / min. Oxygen is introduced during the second-stage sintering process. The sintering temperature is 1400 °C, the heating rate is 4 °C / min, the sintering time is 8 h, the sintering pressure is 200 Pa, the holding time is 6 h, and it is cooled to room temperature with the furnace to obtain a large-sized nickel oxide planar target.

[0075] The preparation method of the slurry containing nickel oxide in this example is as follows:

[0076] (1) Mix 2 g of ethyl methacrylate, 0.4 g of N,N'-methylenebisacrylamide with 90 g of water, stir for 30 min, and adjust the pH to 10 to obtain a mixed solution A;

[0077] (2) Mix 100 g of nickel oxide, 0.75 g of cadmium oxide, 0.25 g of samarium oxide, 0.6 g of polyvinylpyrrolidone, 0.1 g of diethanolamine, 0.3 g of carboxymethyl cellulose with 60 g of water, ultrasonically disperse for 30 min, transfer it to a ball mill and ball mill at a speed of 400 rpm for 10 h to obtain a mixed solution B;

[0078] (3) Mix the mixed solution A and the mixed solution B, ultrasonically disperse for 30 min to obtain a premix, add 0.5 g of benzoyl peroxide and 0.08 g of N,N-dimethylacetamide and ultrasonically disperse for 10 min to obtain a slurry containing nickel oxide.

[0079] Example 4

[0080] The production method of a large-sized nickel oxide planar target in this example is as follows:

[0081] S1: Inject the slurry containing nickel oxide into a mold, dry it in a vacuum oven at 50 °C for 8 h, demold it, and continue to dry it in a vacuum oven at 75 °C for 10 h to obtain a green body;

[0082] S2: Under a neon atmosphere, sinter the green body at 600 °C under normal pressure, with a heating rate of 1.5 °C / min, a holding time of 7 h, and cool it to room temperature in the furnace to obtain the degummed green body; under a neon atmosphere, sinter the degummed green body under normal pressure at a temperature of 900 °C, with a heating rate of 5 °C / min, a holding time of 5 h, and cool it to room temperature in the furnace to obtain the pre-sintered green body;

[0083] S3: Crush the pre-sintered green body, pass it through a 100-mesh sieve to obtain powder, add polyethylene glycol, ball mill it in a ball mill at a speed of 400 rpm for 6 h, granulate it using a spray dryer, pass it through a 150-mesh sieve, and press it into shape using a cold isostatic press at 200 MPa to obtain a secondary green body;

[0084] S4: Transfer the secondary green body to a sintering furnace for sintering. During the first-stage sintering process, neon is introduced, the sintering temperature is 700 °C, the heating rate is 1 °C / min, the holding time is 8 h, and the sintering pressure is 40 Pa; the heating rate from the first-stage sintering temperature to the second-stage sintering temperature is 2 °C / min; during the second-stage sintering process, oxygen is introduced, the sintering temperature is 1350 °C, the heating rate is 3 °C / min, the sintering time is 15 h, the sintering pressure is 350 Pa, the holding time is 8 h, and cool it to room temperature in the furnace to obtain a large-sized nickel oxide planar target.

[0085] The preparation method of the slurry containing nickel oxide in this example is as follows:

[0086] (1) Mix 4 g of ethyl methacrylate, 0.6 g of N,N'-methylenebisacrylamide with 90 g of water, stir for 30 min, and adjust the pH to 10 to obtain mixture A;

[0087] (2) Mix 100 g of nickel oxide, 2.4 g of cadmium oxide, 0.6 g of samarium oxide, 0.35 g of polyvinylpyrrolidone, 0.05 g of diethanolamine, 0.1 g of carboxymethyl cellulose with 60 g of water, ultrasonically disperse for 20 min, transfer to a ball mill and ball mill at a speed of 600 rpm for 15 h to obtain mixture B;

[0088] (3) Mix mixture A and mixture B, ultrasonically disperse for 30 min to obtain a premix, add 0.5 g of benzoyl peroxide and 0.08 g of N,N-dimethylacetamide, and ultrasonically disperse for 10 min to obtain the slurry containing nickel oxide.

[0089] Comparative Example 1

[0090] The difference from Example 1 is that in this comparative example, the mass ratio of the organic monomer to the crosslinking agent is 1:1.

[0091] Comparative Example 2

[0092] The difference from Example 1 is that in this comparative example, the mass ratio of nickel oxide to the sintering aid is 1:0.4.

[0093] Comparative Example 3

[0094] The difference from Example 1 is that in this comparative example, the mass ratio of cadmium oxide to samarium oxide is 1:5.

[0095] Comparative Example 4

[0096] The difference from Example 1 is that in this comparative example, samarium oxide is not added.

[0097] Comparative Example 5

[0098] The difference from Example 1 is that in this comparative example, cadmium oxide is not added.

[0099] Comparative Example 6

[0100] The difference from Example 1 is that in this comparative example, an equal amount of zinc oxide is used to replace cadmium oxide.

[0101] Comparative Example 7

[0102] The difference from Example 1 is that in this comparative example, the mass ratio of polyvinylpyrrolidone, diethanolamine to carboxymethyl cellulose is 1:2:5.

[0103] Comparative Example 8

[0104] The difference from Example 1 is that in this comparative example, no additives are used.

[0105] Comparative Example 9

[0106] The difference from Example 1 is that in this comparative example, ultrasonic dispersion is not carried out in step (2).

[0107] Comparative Example 10

[0108] The difference from Example 1 is that in this comparative example, the temperature of the second-stage sintering is 1700 °C.

[0109] Comparative Example 11

[0110] The difference from Example 1 is that in this comparative example, the mixed solution B is directly granulated using a spray dryer, passed through a 150-mesh sieve, pressed into a shape using a cold isostatic press at 200 MPa, and the obtained green body is subjected to temperature-rising sintering, and the temperature-rising sintering parameters are set the same as in step S4 of Example 1.

[0111] The large-sized nickel oxide planar targets prepared in Examples 1-4 and Comparative Examples 1-11 were subjected to relevant performance tests, and the test results are shown in Table 1.

[0112] Table 1 Test Results

[0113]

[0114] Comparing Comparative Example 1 with Example 1, it can be seen that too much crosslinking agent leads to the formation of a large number of crosslinking points, increasing the viscosity of the slurry, deteriorating the fluidity, and resulting in defects such as uneven local density, which affects the performance of the target.

[0115] Comparing Comparative Example 2 with Example 1, it can be seen that increasing the amount of sintering aid leads to too large a degree of lattice distortion, a decrease in the stability of the lattice, and an increase in the defect density inside the crystal.

[0116] Comparing Comparative Example 3, Comparative Example 4, and Comparative Example 5 with Example 1, it can be seen that changing the ratio of cadmium oxide to samarium oxide reduces the performance of the planar target, proving that the ratio of cadmium oxide to samarium oxide in the present invention reaches the optimum.

[0117] Comparing Comparative Example 6 with Example 1, it can be seen that zinc oxide can also make the relative density of the planar target reach more than 99%, but the improvement of the electrical properties of the planar target by zinc oxide is slightly worse than that of cadmium oxide; when nickel oxide is used as a sintering aid, the energy band interaction between the two is greater than that when zinc oxide is used as a sintering aid in improving the carrier concentration and mobility.

[0118] Comparing Comparative Example 7, Comparative Example 8 with Example 1, it can be seen that increasing the amount of hydroxymethyl cellulose increases the viscosity of the system, reduces the dispersion performance of powders such as nickel oxide, and easily makes the target locally uneven, affecting the performance of the film during the subsequent sputtering process; the presence of additives can significantly improve the dispersion stability of powders such as nickel oxide and improve the performance of the planar target.

[0119] Comparing Comparative Example 9 with Example 1, it can be seen that ultrasonic dispersion can promote the dispersion of powders such as nickel oxide and sintering aid, avoiding agglomeration.

[0120] Comparing Comparative Example 10 with Example 1, it can be seen that a higher sintering temperature easily leads to abnormal grain growth inside the planar target and a decrease in densification.

[0121] Comparing Comparative Example 11 with Example 1, it can be seen that the ceramic densification rate is faster when using gel-casting molding and pre-sintering for the first time, which can reduce the shrinkage of the green body during the subsequent isostatic pressing and heating sintering processes, reduce the internal stress caused by uneven shrinkage, and the grain size is also more uniform; subsequent isostatic pressing can make the green body reach a higher density and uniformity in a shorter time; therefore, in the present invention, gel-casting molding is used for pre-sintering for the first time, and cold isostatic pressing is used for secondary sintering in segments to prepare the target.

[0122] The large-size nickel oxide planar target prepared by the present invention has a low resistivity and a high relative density.

[0123] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Any equivalent transformation or modification made according to the essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A production method of a large-sized nickel oxide planar target, characterized in that, It includes the following steps: S1: Inject the slurry containing nickel oxide into a mold, dry it to obtain a primary green body; S2: Debind the primary green body and then perform pre-sintering in an oxygen-free atmosphere; S3: Crush the pre-sintered primary green body, sieve it to obtain powder, add a binder, mix evenly, granulate, sieve again, and perform cold isostatic pressing to form a secondary green body; S4: Heat the secondary green body for sintering to obtain a large-sized nickel oxide planar target; In the step S1, the preparation method of the slurry containing nickel oxide includes the following steps: (1) Mix the organic monomer, cross-linking agent and water evenly, and adjust the pH to 8 - 10 to obtain a mixed solution A; (2) Mix nickel oxide, sintering aid, additive and water evenly to obtain a mixed solution B; (3) Mix the mixed solution A and the mixed solution B evenly to obtain a premix, add an initiator and a catalyst and mix evenly to obtain the slurry containing nickel oxide; In the step (2), the sintering aid is composed of cadmium oxide and samarium oxide in a mass ratio of (2 - 4)∶1; In the step (2), the additive is composed of polyvinylpyrrolidone, diethylene glycol amine and carboxymethyl cellulose in a mass ratio of (5 - 8)∶1∶(2 - 4).

2. The production method of a large-size nickel oxide planar target according to claim 1, characterized in that The mass ratio of the organic monomer to nickel oxide is (0.015 - 0.04)∶1, and the organic monomer is one of methacrylamide and ethyl methacrylate.

3. A production method of a large-size nickel oxide planar target according to claim 1, characterized in that, In the step (2), the mass ratio of nickel oxide to the sintering aid is 1∶(0.01 - 0.03).

4. A production method of a large-size nickel oxide planar target according to claim 1, characterized in that, In the step (2), the dosage of the additive is 0.5% - 1.5% of the mass of nickel oxide.

5. A production method of a large-size nickel oxide planar target according to claim 1, characterized in that, In the step (2), mixing evenly includes ultrasonic dispersion and ball milling, specifically as follows: The time of ultrasonic dispersion is 20 - 30 min; The speed of ball milling is 400 - 800 rpm, and the time of ball milling is 10 - 15 h.

6. A production method of a large-size nickel oxide planar target according to claim 1, characterized in that In the step S2, the specific steps of pre-sintering are as follows: Perform atmospheric pressure sintering on the primary green body, the temperature is 850 - 900 °C, the heating rate is 3 - 5 °C / min, the holding time is 3 - 5 h, and it is cooled to room temperature with the furnace.

7. The production method of a large-sized nickel oxide planar target according to claim 1, characterized in that, In the step S4, the heating sintering includes a first-stage sintering and a second-stage sintering, specifically as follows: Neon is introduced during the first-stage sintering, the sintering temperature is 500 - 800 °C, the heating rate is 0.5 - 1.5 °C / min, the holding time is 3 - 8 h, and the sintering pressure is 20 - 80 Pa; Oxygen is introduced during the second-stage sintering, the sintering temperature is 1250 - 1350 °C, the heating rate is 3 - 5 °C / min, the sintering time is 8 - 20 h, the sintering pressure is 200 - 500 Pa, and the holding time is 2 - 8 h; The heating rate from the first-stage sintering temperature to the second-stage sintering temperature is 2 °C / min.

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