Praseodymium-doped yttrium iron garnet photosensitive sol, thin film fine pattern and preparation method thereof

Abstract

The invention provides a praseodymium-doped yttrium iron garnet photosensitive sol, a film fine pattern and a preparation method of the praseodymium-doped yttrium iron garnet photosensitive sol. Y (C2H3O2) 3, Pr (NO3) 3.6 H2O and Fe (NO3) 3.9 H2O are used as raw materials, propionic acid is used as a catalyst, benzoylacetone is used as a photosensitive chelating agent, methanol is used as a solvent, the raw materials are mixed, methanol is added for volume metering, and the Y2.85Pr0.15 Fe5O12 photosensitive sol is obtained after aging. Y2.85Pr0. 15Fe5O12 photosensitive sol is used as a precursor, a gel film is dip-coated on a substrate by adopting a dip-coating method, and the Y2.85Pr0. 15Fe5O12 thin film fine pattern is obtained by drying, exposing, dissolving and washing and annealing. The Y2. 85Pr0. 15Fe5O12 ultraviolet photosensitive sol prepared by the preparation method disclosed by the invention is stable, and a gel film with a relatively large size can be obtained; the preparation process is simple, and a large-area Y < 2.85 > Pr < 0.15 > Fe < 5 > O < 12 > fine pattern can be prepared; the prepared Y2. 85Pr0. 15Fe5O12 fine pattern is complete in structure and clear in outline; according to the method, the problems that in a traditional preparation method, the morphology of a fine pattern of the Y2. 85Pr0. 15Fe5O12 film is damaged, and the saturation magnetization intensity is reduced are solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of thin film material patterning, and particularly relates to a praseodymium-doped yttrium iron garnet photosensitive sol, a thin film micro-pattern and a preparation method thereof. BACKGROUND

[0002] Praseodymium-doped yttrium iron garnet (Y 2.85 Pr 0.15 Fe5O 12 ) ferromagnetic material has high Curie temperature, high resistivity, low loss, moderate saturation magnetization and other advantages, and is widely used in radar, electronic navigation and other microelectronic fields, such as inductors, circulators, isolators and other microelectronic devices.

[0003] Praseodymium-doped yttrium iron garnet is a kind of garnet oxide, and has become a research hotspot due to its excellent microwave electromagnetic properties. In particular, with the urgent demand for device integration in modern technology, the research on thin film materials is more important. In the application process, it is often necessary to perform microfabrication on it, so as to manufacture different types and different functions of micro devices, such as thin film inductors. The traditional method for preparing micro-patterns includes photoresist-wet chemical etching and focused ion beam etching. Although these methods can obtain micron-level thin film micro-patterns, the microfabrication by these methods is performed after the preparation of the thin film, and the chemical agent or ion beam will cause damage to the structure and morphology of the thin film, thereby reducing the performance of the device. The photosensitive sol method uses a photosensitive sol to prepare a gel film, and forms two regions with different solubilities (exposed region and unexposed region) under ultraviolet light exposure. After development and heat treatment, a thin film micro-pattern is obtained. This method integrates the preparation and microfabrication of the thin film into one step, and can effectively avoid the above problems.

[0004] The yttrium iron garnet sol in the prior art document "Tejing Jiao, Caiyin You, Na Tian, Zongfan Duan, Fuxue Yan, Structural distortion induced enhancement of magnetic and dielectric properties in Pr modified yttrium iron garnet films [J], Ceramics International, 2023, 49: 10129-10138" does not have photosensitivity. The yttrium iron garnet sol in the prior art patent application (publication number: CN104193316A) is prepared by dissolving yttrium oxide in a mixed solvent of acetic acid and water, and part of the yttrium acetate generated in the reaction is used as the yttrium salt raw material. However, due to insufficient reaction conditions, the reaction is not complete, and a large amount of yttrium oxide remains in the solution. Therefore, the sol still needs to be filtered to remove the precipitate (i.e. unreacted yttrium oxide) after standing for 48-72 hours. The operation steps are complex, and the content of yttrium acetate cannot be accurately controlled.

[0005] Y 2.85 Pr 0.15 Fe5O 12 Micro-patterning of thin film materials is the basis for their application in electronic devices. To obtain specific shapes of micro-patterns, the key lies in the micro-fabrication process of thin film materials. Traditional micro-fabrication methods (such as photoresist-wet chemical etching, focused ion beam etching, etc.) can obtain micron-level thin film micro-patterns, but cannot avoid the damage to the morphology and performance of the thin film caused by chemical agents or ion beams.

[0006] Currently, functional oxide thin films such as CoFe2O4 are micro-fabricated using photosensitive sol method. The CoFe2O4 photosensitive sol in the prior art patent application (publication number: CN108149228A) uses acetylacetone as a chelating agent, which has poor photosensitivity and poor sol stability. Therefore, citric acid is added as a stabilizer to extend the use time of the sol. In addition, the solvent used to prepare the CoFe2O4 micro-pattern in this patent application is a mixture of ethanol and isopropanol with a ratio of 1: (20-100). Since isopropanol has weak polarity, its addition amount is large, and further optimization is still needed. In addition, the thin film micro-patterns prepared by this patent application have a low heat treatment temperature of 300-750°C and a short holding time of 10-180 min. A low temperature and a short holding time will result in poor crystallinity and small grain size of the thin film, which will reduce the physical properties of the thin film micro-patterns prepared. Therefore, based on the results reported by this research, the existing photosensitive sol technology still needs to be improved.

[0007] At present, there are many reports on A-site (i.e. Y-site) doping of yttrium iron garnet (Y3Fe5O 12 12) and it is confirmed that doping Pr 3+ will cause lattice expansion of YIG, which is beneficial to the improvement of the magnetic properties of YIG film. However, there is no report on the microfabrication of Y 2.85 Pr 0.15 Fe5O 12 thin film material, especially the microfabrication of Y 2.85 Pr 0.15 Fe5O 12 thin film by using photosensitive sol method. SUMMARY

[0008] The present application aims to provide a kind of yttrium iron garnet photosensitive sol doped with praseodymium, thin film micro-pattern and preparation method thereof, to overcome the problem that yttrium iron garnet component deviates from actual value in traditional sol preparation method, and the problem that chelating agent photosensitivity is weak, in addition to overcome the problem that the structure, morphology of praseodymium-doped yttrium iron garnet thin film micro-pattern is damaged and the problem that saturation magnetization is reduced.

[0009] The present application is realized by the following technical solutions: A preparation method of yttrium iron garnet photosensitive sol doped with praseodymium, comprising the following steps: Step 1, Y (C2H3O2) 3 and propionic acid are added to anhydrous methanol, stirred at room temperature until clear, to obtain a yttrium salt solution; Pr (NO3) 3·6H2O is added to anhydrous methanol, stirred at room temperature until clear, to obtain a praseodymium salt solution; Fe (NO3) 3·9H2O is added to anhydrous methanol, stirred at room temperature until clear, to obtain an iron salt solution; benzoylacetone is added to anhydrous methanol, stirred at room temperature until clear, to obtain a benzoylacetone solution; Step 2, the yttrium salt solution, the praseodymium salt solution, the iron salt solution and the benzoylacetone solution are mixed, anhydrous methanol is added to adjust the total metal ion concentration to 0.3 mol / L-0.5 mol / L, stirred and aged at room temperature, to obtain a Y 2.85 Pr 0.15 Fe5O 12 photosensitive sol.

[0010] Further, in the preparation of the yttrium salt solution, the molar ratio between Y (C2H3O2) 3, propionic acid and anhydrous methanol is 1: (2-5): (15-35); In the preparation of the praseodymium salt solution, the molar ratio between Pr (NO3) 3·6H2O and methanol is 1: (10-20).

[0011] Further, in the preparation of the iron salt solution, the molar ratio between Fe (NO3) 3·9H2O and methanol is 1: (10-20). In the preparation of the benzoylacetone solution, the molar ratio of benzoylacetone, Y(C2H3O2)3 used in the preparation of the yttrium salt solution and anhydrous methanol is (1-2):1:(10-20).

[0012] Further, the molar ratio of Y 3+ , Pr 3+ , Fe 3 and benzoylacetone in the yttrium salt solution, praseodymium salt solution, iron salt solution and benzoylacetone solution is 2.85:0.15:5:(3-6).

[0013] Further, the stirring at room temperature in step 2 is for 6-8 h and the aging is for 24-36 h.

[0014] A praseodymium-doped yttrium iron garnet photosensitive sol is prepared by the above method.

[0015] A method for preparing a praseodymium-doped yttrium iron garnet magnetic film micro-pattern, comprising the following steps: Step a, using Y 2.85 Pr 0.15 Fe5O 12 photosensitive sol as a precursor, Y 2.85 Pr 0.15 Fe5O 12 gel film is coated on a substrate by dip-coating method, and then the Y 2.85 Pr 0.15 Fe5O 12 gel film is dried; Step b, a mask plate in the shape of dot array or sun is placed on the dried Y 2.85 Pr 0.15 Fe5O 12 gel film, and the dried Y 2.85 Pr 0.15 Fe5O 12 gel film is exposed to ultraviolet light; Step c, the exposed Y 2.85 Pr 0.15 Fe5O 12 gel film obtained in step b is immersed in a washing agent, then taken out and blown dry with nitrogen; 2.85 Pr 0.15 Fe5O 12 gel film after washing; Step d, the film obtained in step c is annealed to obtain a Y 2.85 Pr 0.15 Fe5O 12 film micro-pattern.

[0016] Further, the substrate used in step a is a silicon substrate or a quartz substrate, the pulling rate is 0.5-3 mm / s, the drying temperature is 60-100 DEG C, and the drying time is 5-30 min. The exposure time in step b is 30-90 min.

[0017] Further, the dissolving agent used in step c is a mixed solution of anhydrous ethanol and n-butanol with a volume ratio of 1: (5-20), and the dissolving time is 3-15 s. The annealing temperature in step d is 700-850 DEG C, and the time is 3-5 h.

[0018] Compared with the prior art, the present application has the following beneficial technical effects: The present application directly uses yttrium acetate as a yttrium salt raw material, and Y 2.85 Pr 0.15 Fe5O 12 thin film, a chemical modifier (benzoyl acetone) is added to Y 2.85 Pr 0.15 Fe5O 12 sol, the obtained Y 2.85 Pr 0.15 Fe5O 12 The photosensitive sol has better photosensitivity, and the sol is more stable, without adding other stabilizers, in the reaction process, yttrium ions will undergo chelation reaction with benzoyl acetone to generate metal coordination chelate containing yttrium metal ions, and the coordination chelation reaction is as follows:

[0019] The Y 2.85 Pr 0.15 Fe5O 12 photosensitive sol is used to prepare a gel film, under the irradiation of an ultraviolet lamp, the characteristic absorption peak gradually disappears, which indicates that Y 2.85 Pr 0.15 Fe5O 12 The gel thin film shows obvious photosensitivity, and with the extension of the ultraviolet light irradiation time, the yttrium-containing chelate is photolyzed, and the structure change is as follows:

[0020] The Y 2.85 Pr 0.15 Fe5O 12 The ultraviolet photosensitive sol is stable, and a gel film with a large size can be obtained by the dip-coating method, and the thickness of the thin film is easy to control.

[0021] The present application combines the chemical modification method with the sol-gel method, and Y 2.85 Pr 0.15 Fe5O12 The ferromagnetic thin film and micro-pattern are prepared simultaneously, the preparation process is simple, and large-area Y 2.85 Pr 0.15 Fe5O 12 The micro-pattern is prepared, and the obtained Y 2.85 Pr 0.15 Fe5O 12 The micro-pattern structure is complete and the outline is clear; the Y 2.85 Pr 0.15 Fe5O 12 The appearance and performance of the thin film micro-pattern are damaged, and the application prospect in the field of microelectronic devices is wide. The micro-fabrication step of the traditional micro-pattern preparation method is carried out after the preparation of the thin film, and the structure and appearance of the thin film are damaged by chemical agents or ion beams, thereby reducing the performance of the device. The preparation of the thin film and the micro-fabrication are integrated into one step in the present application, which can effectively avoid the above problems. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced below, and the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0023] Figure 1 Y is prepared in Example 1 3+ / benzoylacetone sol, Y 2.85 Pr 0.15 Fe5O 12 The ultraviolet absorption spectrum of the photosensitive sol; Figure 2 Y is prepared in Example 1 2.85 Pr 0.15 Fe5O 12 The ultraviolet absorption spectrum of the gel film under different ultraviolet exposure times; Figure 3 Y is prepared in Example 1 2.85 Pr 0.15 Fe5O 12 The X-ray diffraction pattern of the thin film micro-pattern; Figure 4 (a) is the Y 2.85 Pr 0.15 Fe5O 12 The laser confocal photo of the thin film micro-pattern; Figure 4 (b) is the Y 2.85 Pr 0.15 Fe5O 12Laser confocal photo of thin film micro-pattern; Figure 4(c) is Y 2.85 Pr 0.15 Fe5O 12 Laser confocal photo of thin film micro-pattern; Figure 4(d) is Y 2.85 Pr 0.15 Fe5O 12 Laser confocal photo of thin film micro-pattern; Figure 5 Y 2.85 Pr 0.15 Fe5O 12 Thin film micro-pattern room temperature in-plane hysteresis loop. DETAILED DESCRIPTION

[0024] The present application will be described in detail as follows: A preparation method of a praseodymium-doped yttrium iron garnet photosensitive sol, comprising the following steps: Step 1, Y(C2H3O2)3 and propionic acid are added to anhydrous methanol according to a molar ratio of Y(C2H3O2)3, propionic acid and methanol of 1: (2-5): (15-35), and stirred at room temperature for 40-80 min until clear to obtain a yttrium salt solution; Pr(NO3)3·6H2O is added to anhydrous methanol according to a molar ratio of Pr(NO3)3·6H2O and methanol of 1: (10-20), and stirred at room temperature for 5-15 min until clear to obtain a praseodymium salt solution; Fe(NO3)3·9H2O is added to anhydrous methanol according to a molar ratio of Fe(NO3)3·9H2O and methanol of 1: (10-20), and stirred at room temperature for 5-15 min until clear to obtain an iron salt solution; Benzoylacetone is added to anhydrous methanol according to a molar ratio of benzoylacetone, Y(C2H3O2)3 in the yttrium salt solution and methanol of (1-2): 1: (10-20), and stirred at room temperature for 15-30 min until clear to obtain a benzoylacetone solution; Step 2, Y 3+ : Pr 3+ : Fe 3+The molar ratio of benzoylacetone is 2.85:0.15:5:(3-6), the yttrium salt solution, praseodymium salt solution, iron salt solution and benzoylacetone solution are mixed, stirred at room temperature for 5-15 min, then a certain amount of anhydrous methanol is added to adjust the total metal ion concentration to 0.3 mol / L-0.5 mol / L, stirred at room temperature for 6-8 h, and then aged for 24-36 h to obtain Y 2.85 Pr 0.15 Fe5O 12 Photosensitive sol.

[0025] The present application also uses the above Y 2.85 Pr 0.15 Fe5O 12 Photosensitive sol. Step a, using the Y 2.85 Pr 0.15 Fe5O 12 Photosensitive sol. obtained by the above method as a precursor, using the dip-coating method, and immersing and coating Y 2.85 Pr 0.15 Fe5O 12 Gel film on a silicon substrate or a quartz substrate at a pulling rate of 0.5-3 mm / s, and then placing the gel film in a drying oven at 60-100 DEG C and drying for 5-30 min; Step b, placing a mask plate in the shape of an array or a sun on the dried Y 2.85 Pr 0.15 Fe5O 12 Gel film, and exposing the Y 2.85 Pr 0.15 Fe5O 12 Gel film obtained in step a to ultraviolet light, and the exposure time is 30-90 min; Step c, placing the exposed Y 2.85 Pr 0.15 Fe5O 12 Gel film obtained in step b in a mixed solution of anhydrous ethanol and n-butanol in a volume ratio of 1:5-20, and then taking out, and then blowing the washed Y 2.85 Pr 0.15 Fe5O 12 Gel film dry with nitrogen; Step d, annealing the thin film obtained in step c at 700-850 DEG C for 3-5 h to obtain a crystalline Y 2.85 Pr 0.15 Fe5O 12 Thin film micro-pattern.

[0026] The present application uses a chemical modification method combined with a sol-gel method to prepare Y2.85 Pr 0.15 Fe5O 12 Micro-pattern, micro-fabrication process is in Y 2.85 Pr 0.15 Fe5O 12 The chemical modifier is added in the precursor, which coordinates with yttrium metal ion to form a chelate, under ultraviolet light irradiation, the yttrium-containing chelate is photolyzed, causing the solubility in organic solvent to be reduced, and the solubility difference between the partially insoluble and the easily soluble unexposed part can be used to prepare the required micro-pattern. The method does not need photoresist and etchant, and overcomes many shortcomings of traditional micro-fabrication process, and the prepared Y 2.85 Pr 0.15 Fe5O 12 The thin film micro-pattern has complete structure and clear profile.

[0027] The embodiments of the present application will be described in detail below with examples. The examples are preferred embodiments of the present application, and cannot limit the scope of the present application. In the following examples, the methods and experimental apparatuses used are conventional methods and apparatuses if not specifically stated.

[0028] Example 1 A preparation method of a praseodymium-doped yttrium iron garnet photosensitive sol, comprising the following steps: Step 1, according to the molar ratio of Y(C2H3O2)3, propionic acid and methanol is 1:3:20, Y(C2H3O2)3 and propionic acid are added to anhydrous methanol, stirred at room temperature for 50 min, to obtain a yttrium salt solution; According to the molar ratio of Pr(NO3)3·6H2O and methanol is 1:10, Pr(NO3)3·6H2O is added to anhydrous methanol, stirred at room temperature for 15 min to be clear, to obtain a praseodymium salt solution; According to the molar ratio of Fe(NO3)3·9H2O and methanol is 1:10, Fe(NO3)3·9H2O is added to anhydrous methanol, stirred at room temperature for 15 min, to obtain an iron salt solution; According to the molar ratio of benzoylacetone, Y(C2H3O2)3 in the yttrium salt solution and anhydrous methanol is 1:1:10, benzoylacetone is added to anhydrous methanol, stirred at room temperature for 15 min, to obtain a benzoylacetone solution; Step 2, according to the molar ratio of Y 3+ : Pr 3+ : Fe 3+: 2.85 : 0.15 : 5 : 3, the yttrium salt solution, praseodymium salt solution, iron salt solution and benzoylacetone solution were mixed, stirred at room temperature for 5 min, then a certain amount of anhydrous methanol was added to adjust the total metal ion concentration to 0.3 mol / L, stirred at room temperature for 6 h, and aged for 24 h to obtain Y 2.85 Pr 0.15 Fe5O 12 photographic sol.

[0029] Step 3, according to the molar ratio of Y(C2H3O2)3, benzoylacetone, propionic acid and methanol 1 : 1 : 3 : 20, Y(C2H3O2)3, benzoylacetone and propionic acid were added to anhydrous methanol, stirred at room temperature for 6 h to obtain Y 3+ / benzoylacetone sol.

[0030] Figure 1 Y 2.85 Pr 0.15 Fe5O 12 photographic sol. 3+ / benzoylacetone sol., Y 2.85 Pr 0.15 Fe5O 12 photographic sol., their π-π* transition absorption peaks are all near the wavelength of 330 nm, compared with the absorption peak of the benzoylacetone solution, it is rightward shifted by about 20 nm, indicating that chelation reaction occurs during stirring, generating metal coordination chelate containing yttrium metal ions, and the chelation reaction is as follows:

[0031] The Y 2.85 Pr 0.15 Fe5O 12 photographic sol. was used to prepare thin film micro-patterns: The Y 2.85 Pr 0.15 Fe5O 12 gel film was drawn on a silicon substrate by dip-coating method at a drawing rate of 2 mm / s, and then dried at a temperature of 80 ℃ for 10 min, and a mask plate with an array was placed on the dried Y 2.85 Pr 0.15 Fe5O 12The gel film is exposed to UV light for 60 min, then washed in a 1:5 volume ratio of anhydrous ethanol and n-butanol for 5 s, and then the surface residues are blown dry with high-purity nitrogen gas. The desired pattern is left, and the Y 2.85 Pr 0.15 Fe5O 12 thin film micro-pattern.

[0032] Figure 2 The Y 2.85 Pr 0.15 Fe5O 12 gel film under different UV exposure times, from Figure 2 It can be found that the Y 2.85 Pr 0.15 Fe5O 12 main absorption peak at 330 nm gradually weakens as the UV exposure time increases from 20 min to 120 min, and the absorption peak becomes flat after 120 min of exposure, indicating that the Y 2.85 Pr 0.15 Fe5O 12 sol has UV photosensitivity; Figure 3 The Y 2.85 Pr 0.15 Fe5O 12 thin film pattern has a strong diffraction peak intensity, and the diffraction peak position is consistent with the characteristic peak position of the Y 2.85 Pr 0.15 Fe5O 12 standard card (card number: 43-507), and no diffraction peaks related to other impurities are observed, indicating that the phase of the prepared pattern thin film is garnet phase; Figure 4 (a) is a laser confocal photo of the Y 2.85 Pr 0.15 Fe5O 12 thin film micro-pattern prepared in this example, with a dot array diameter of 50 μm. The outline of the pattern is clear and the structure is complete; Figure 5 The Y 2.85 Pr 0.15 Fe5O 12 thin film pattern prepared in this example has a room temperature in-plane hysteresis loop, with a saturation magnetization of about 241 emu / cm 3 , which is comparable to the value before microfabrication, indicating that the pattern obtained by this method retains the original magnetic properties of the thin film.

[0033] Example 2 A preparation method of a praseodymium-doped yttrium iron garnet photosensitive sol, comprising the following steps: Step 1, Y(C2H3O2)3, propionic acid and methanol are added to anhydrous methanol according to a molar ratio of 1:2:15, stirred at room temperature for 40 min to obtain a yttrium salt solution; Pr(NO3)3·6H2O is added to anhydrous methanol according to a molar ratio of 1:14, stirred at room temperature until clear for 12 min to obtain a praseodymium salt solution; Fe(NO3)3·9H2O is added to anhydrous methanol according to a molar ratio of 1:14, stirred at room temperature for 12 min to obtain an iron salt solution; Benzoylacetone is added to anhydrous methanol according to a molar ratio of 1.2:1:12 of benzoylacetone, Y(C2H3O2)3 in the yttrium salt solution and anhydrous methanol, stirred at room temperature for 20 min to obtain a benzoylacetone solution; Step 2, the yttrium salt solution, the praseodymium salt solution, the iron salt solution and the benzoylacetone solution are mixed according to a molar ratio of Y 3+ : Pr 3+ : Fe 3+ : benzoylacetone in the yttrium salt solution, the praseodymium salt solution, the iron salt solution and the benzoylacetone solution is 2.85:0.15:5:3.6, the yttrium salt solution, the iron salt solution and the benzoylacetone solution are mixed, stirred at room temperature for 8 min, then a certain amount of anhydrous methanol is added to adjust the total metal ion concentration to 0.35 mol / L, stirred at room temperature for 7 h, aged for 28 h to obtain a Y 2.85 Pr 0.15 Fe5O 12 photosensitive sol.

[0034] A thin film micro-pattern is prepared by using the Y 2.85 Pr 0.15 Fe5O 12 photosensitive sol. A Y 2.85 Pr 0.15 Fe5O 12 gel film is drawn on a silicon substrate by a dip-coating method at a drawing rate of 0.5 mm / s, then a mask plate with a dot matrix is placed on the dried Y 2.85 Pr 0.15 Fe5O 12The gel film is exposed to UV light for 30 min, then washed in a 1:10 volume ratio of anhydrous ethanol and n-butanol for 3 s, and then the surface residues are blown dry with high-purity nitrogen gas to leave the desired pattern. The pattern is then annealed at 700 ℃ for 3 h to obtain Y 2.85 Pr 0.15 Fe5O 12 thin-film micro-pattern.

[0035] Fig. 4(b) is a laser confocal photo of the Y 2.85 Pr 0.15 Fe5O 12 thin-film micro-pattern prepared in this embodiment, with a dot array diameter of 30 μm. The pattern outline is clear and the structure is complete.

[0036] Embodiment 3 A method for preparing a praseodymium-doped yttrium iron garnet photosensitive sol, comprising the following steps: Step 1. Y(C2H3O2)3, propionic acid and methanol are added to anhydrous methanol in a molar ratio of 1:4:25, and stirred at room temperature for 60 min to obtain a yttrium salt solution; Pr(NO3)3·6H2O and methanol are added to anhydrous methanol in a molar ratio of 1:18, and stirred at room temperature until clear for 10 min to obtain a praseodymium salt solution; Fe(NO3)3·9H2O and methanol are added to anhydrous methanol in a molar ratio of 1:18, and stirred at room temperature for 10 min to obtain an iron salt solution; benzoylacetone, Y(C2H3O2)3 in the yttrium salt solution and anhydrous methanol are added to anhydrous methanol in a molar ratio of 1.4:1:15, and stirred at room temperature for 25 min to obtain a benzoylacetone solution; Step 2. Y 3+ : Pr 3+ : Fe 3+ : benzoylacetone in the yttrium salt solution, the praseodymium salt solution, the iron salt solution and the benzoylacetone solution are mixed in a molar ratio of 2.85:0.15:5:4.2, and stirred at room temperature for 10 min. Then a certain amount of anhydrous methanol is added to adjust the total metal ion concentration to 0.4 mol / L, and stirred at room temperature for 7.5 h. After aging for 32 h, a Y 2.85 Pr 0.15 Fe5O 12 photosensitive sol is obtained.

[0037] A Y 2.85 Pr 0.15 Fe5O 12 A thin film micro-pattern is prepared by using the photosensitive sol A Y 2.85 Pr 0.15 Fe5O 12 A gel film is prepared, and then dried at a temperature of 70 ℃ for 15 min, a mask plate with a sun shape is placed above the dried Y 2.85 Pr 0.15 Fe5O 12 A gel film is prepared, and then dried at a temperature of 70 ℃ for 15 min, a mask plate with a sun shape is placed above the dried Y 2.85 Pr 0.15 Fe5O 12 A thin film micro-pattern is prepared by using the photosensitive sol

[0038] Fig. 4 (c) is a laser confocal photo of the Y 2.85 Pr 0.15 Fe5O 12 A thin film micro-pattern is prepared by using the photosensitive sol

[0039] Example 4 A preparation method of a photosensitive sol of a praseodymium-doped yttrium iron garnet, comprising the following steps: Step 1, Y (C2H3O2) 3, propionic acid and methanol are added to anhydrous methanol according to a molar ratio of 1:5:35, and stirred at room temperature for 80 min to obtain a yttrium salt solution; Pr (NO3) 3·6H2O is added to anhydrous methanol according to a molar ratio of 1:20, and stirred at room temperature until clear for 5 min to obtain a praseodymium salt solution; Fe (NO3) 3·9H2O is added to anhydrous methanol according to a molar ratio of 1:20, and stirred at room temperature for 5 min to obtain an iron salt solution; Benzoylacetone is added to anhydrous methanol according to a molar ratio of 2:1:20, and stirred at room temperature for 30 min to obtain a benzoylacetone solution; Step 2, Y 3+ : Pr3+ : Fe 3+ : The molar ratio of benzoylacetone is 2.85:0.15:5:6, the yttrium salt solution, the iron salt solution and the benzoylacetone solution are mixed, stirred at room temperature for 15 min, then a certain amount of anhydrous methanol is added to adjust the total metal ion concentration to 0.5 mol / L, stirred at room temperature for 8 h, and after aging for 36 h, Y 2.85 Pr 0.15 Fe5O 12 photographic sol.

[0040] The Y 2.85 Pr 0.15 Fe5O 12 photographic sol. is prepared into a thin film micro-pattern by using the above method: The Y 2.85 Pr 0.15 Fe5O 12 gel film is prepared by using the dip-coating method, and then dried at a temperature of 100 ℃ for 30 min, a mask plate with a sun shape is placed above the dried Y 2.85 Pr 0.15 Fe5O 12 gel film, and then exposed to light under a UV lamp for 90 min, then washed in a solvent washing agent composed of anhydrous ethanol and n-butanol in a volume ratio of 1:20 for 15 s, after being taken out, the surface residues are blown dry with high-purity nitrogen, and the required pattern is left, and then annealed at 850 ℃ for 4.5 h, to obtain a Y 2.85 Pr 0.15 Fe5O 12 thin film micro-pattern.

[0041] Fig. 4 (d) is a laser confocal photo of the Y 2.85 Pr 0.15 Fe5O 12 thin film micro-pattern with a sun shape prepared in the embodiment, and it can be observed that the outline of the pattern is clear and the structure is complete.

[0042] The present application provides a preparation method of a Y 2.85 Pr 0.15 Fe5O 12 thin film micro-pattern, which can conveniently and quickly prepare a Y 2.85 Pr 0.15 Fe5O 12 micro-pattern, and the preparation process does not affect the performance of the Y 2.85 Pr 0.15 Fe5O 12 thin film, and can be applied to the preparation of a Y 2.85 Pr 0.15 Fe5O 12Magnetic device for media.

[0043] Although the present application has been disclosed in its preferred embodiments with reference to the accompanying drawings, it is to be understood that the application is not limited to those precise embodiments, and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope or spirit of the application, which scope is defined by the claims.

Claims

1. A method for preparing a praseodymium-yttrium-iron garnet photosensitive sol, characterized in that, Includes the following steps: Step 1: Add Y(C2H3O2)3 and propionic acid to anhydrous methanol and stir at room temperature until clear to obtain a yttrium salt solution; add Pr(NO3)3·6H2O to anhydrous methanol and stir at room temperature until clear to obtain a praseodymium salt solution; add Fe(NO3)3·9H2O to anhydrous methanol and stir at room temperature until clear to obtain an iron salt solution; add benzoylacetone to anhydrous methanol and stir at room temperature until clear to obtain a benzoylacetone solution. Step 2: Mix the yttrium salt solution, praseodymium salt solution, ferric salt solution, and benzoylacetone solution, add anhydrous methanol to adjust the total metal ion concentration to 0.3 mol / L~0.5 mol / L, stir and age at room temperature to obtain Y. 2.85 Pr 0.15 Fe5O 12 Photogel.

2. The method for preparing a praseodymium-yttrium-iron garnet photosensitive sol according to claim 1, characterized in that, In the preparation of yttrium salt solution, the molar ratio between Y(C2H3O2)3, propionic acid and anhydrous methanol is 1:(2~5):(15~35). In the preparation of praseodymium salt solution, the molar ratio between Pr(NO3)3·6H2O and methanol is 1:(10~20).

3. The method for preparing a praseodymium-yttrium-iron garnet photosensitive sol according to claim 1, characterized in that, In the preparation of iron salt solution, the molar ratio between Fe(NO3)3·9H2O and methanol is 1:(10~20). When preparing benzoylacetone solution, the molar ratio between benzoylacetone, Y(C2H3O2)3 used in preparing yttrium salt solution and anhydrous methanol is (1~2):1:(10~20).

4. The method for preparing a praseodymium-yttrium-iron garnet photosensitive sol according to claim 1, characterized in that, The yttrium salt solution, praseodymium salt solution, iron salt solution, and benzoyl acetone solution contain Y 3+ Pr 3+ Fe 3 The molar ratio of benzoylacetone is 2.85 : 0.15 : 5 : (3~6).

5. The method for preparing a praseodymium-yttrium-iron garnet photosensitive sol according to claim 1, characterized in that, In step 2, stir at room temperature for 6-8 hours and age for 24-36 hours.

6. A praseodymium-yttrium-iron garnet photosensitive sol, characterized in that, It is prepared by the preparation method according to any one of claims 1-5.

7. A method for preparing fine patterns of praseodymium-doped yttrium iron garnet magnetic thin films, based on the praseodymium-doped yttrium iron garnet photosensitive sol described in claim 6, characterized in that, Includes the following steps: Step a, using Y 2.85 Pr 0.15 Fe5O 12 Photosensitive sol was used as a precursor, and Y was dip-coated onto the substrate using the dip-coating method. 2.85 Pr 0.15 Fe5O 12 Gel membrane, then Y 2.85 Pr 0.15 Fe5O 12 Drying the gel membrane; Step b: Place the dot-matrix or sun-shaped mask onto the dried Y-shaped mask. 2.85 Pr 0.15 Fe5O 12 On the gel membrane, UV light was used to irradiate the dried Y... 2.85 Pr 0.15 Fe5O 12 Expose the gel film; Step c, take the exposed Y obtained in step b 2.85 Pr 0.15 Fe5O 12 The gel membrane was washed in a solvent, then removed, and finally sterilized with nitrogen gas. 2.85 Pr 0.15 Fe5O 12 Dry the gel film; Step d: Anneal the film obtained in step c to obtain Y. 2.85 Pr 0.15 Fe5O 12 Thin film micro-patterns.

8. A method for preparing fine patterns of praseodymium-doped yttrium iron garnet magnetic thin films according to claim 7, characterized in that, The substrate used in step a is a silicon substrate or a quartz substrate, the pulling speed is 0.5~3 mm / s, the drying temperature is 60~100 ℃, and the drying time is 5~30 min; The exposure time in step b is 30~90 min.

9. A method for preparing fine patterns of praseodymium-doped yttrium iron garnet magnetic thin films according to claim 7, characterized in that, In step c, the solvent is a mixed solution of anhydrous ethanol and n-butanol with a volume ratio of 1:(5~20), and the washing time is 3~15 s; In step d, the annealing temperature is 700~850 ℃ and the time is 3~5 h.

10. A praseodymium-doped yttrium iron garnet magnetic thin film micropattern, characterized in that, The micro-pattern of praseodymium-doped yttrium iron garnet magnetic thin film was prepared using the method described in any one of claims 7-9.

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