阅读说明：本技术 一种钐掺杂pzt压电纳米粉体及其制备方法和应用 (Samarium-doped PZT piezoelectric nano powder and preparation method and application thereof ) 是由 张军 李向东 任奕飞 罗福康 王祥达 何建方 李建霖 于 2021-07-15 设计创作，主要内容包括：本发明提供了一种钐掺杂PZT压电纳米粉体及其制备方法和应用。本发明通过水热掺杂工艺并添加烷基聚氧乙烯醚的方式制备得到钐掺杂PZT压电纳米粉体,可有效减小所制备粉体材料的粒径,并对应提高其压电性能；且制备方法简单,成本低。该钐掺杂PZT压电粉体的粒径为300～400nm；压电常数d-(33)高达510pC/N,将其制备成压电陶瓷可有效用于压电器件。(The invention provides samarium-doped PZT piezoelectric nano powder and a preparation method and application thereof. According to the preparation method, the samarium-doped PZT piezoelectric nano powder is prepared by a hydrothermal doping process and adding alkyl polyoxyethylene ether, so that the particle size of the prepared powder material can be effectively reduced, and the piezoelectric performance of the powder material is correspondingly improved; and the preparation method is simple and low in cost. The particle size of the samarium-doped PZT piezoelectric powder is 300-400 nm; piezoelectric constant d 33 Up to 510pC/N, and can be effectively used in piezoelectric devices.)

1. A preparation method of samarium-doped PZT piezoelectric nano powder is characterized by comprising the following steps:

s1: mixing tetrabutyl titanate, a water-based wetting dispersant, a zirconium salt and a precipitator, and carrying out coprecipitation reaction;

s2: adding lead salt, alkyl polyoxyethylene ether, samarium salt and a mineralizer into a product obtained by the S1 coprecipitation reaction, carrying out mineralization reaction, carrying out hydrothermal reaction, and drying to obtain samarium-doped PZT piezoelectric nano powder;

wherein the molecular formula of the samarium-doped PZT piezoelectric nano powder is Pb_1-xSm_x(Zr_0.52Ti_0.48)O₃，0.01≤x≤0.05。

2. The method according to claim 1, wherein the zirconium salt is at least one of zirconyl nitrate or zirconium oxychloride; the lead salt is lead nitrate; the samarium salt is samarium nitrate.

3. The method according to claim 1, wherein the aqueous wetting dispersant in S1 is polyethylene glycol; the precipitant is ammonia water.

4. The preparation method according to claim 1, wherein the specific steps of the coprecipitation reaction in S1 are as follows: tetrabutyl titanate, a water-based wetting dispersant, a zirconium salt and a precipitator are mixed, the pH value of the solution is adjusted to 7-10 by the precipitator, and the reaction lasts for 1.0-2.5 h.

5. The method according to claim 1, wherein the mass ratio of the alkyl polyoxyethylene ether to the lead salt in S2 is 1000: 1-5.

6. The preparation method according to claim 1, wherein the specific steps of S2 are as follows: sequentially adding lead salt and alkyl polyoxyethylene ether into the product obtained in S1, uniformly stirring, adding samarium salt, dropwise adding a mineralizer, and stirring for mineralization reaction; then carrying out hydrothermal reaction to obtain the samarium-doped PZT piezoelectric nano powder.

7. The method according to claim 1, wherein the mineralizer in S2 is KOH; the specific steps of the mineralization reaction are as follows: adding mineralizer to regulate the pH value of the mixed solution to 10-12, and then stirring and reacting for 20-60 min.

8. The preparation method as claimed in claim 1, wherein the hydrothermal reaction in S2 is carried out at a temperature of 180 ℃ and a temperature of 220 ℃ for a reaction time of 10-15 h.

9. A samarium-doped PZT piezoelectric nano powder, characterized by being prepared by the preparation method of any one of claims 1 to 8.

10. The use of the samarium-doped PZT piezoelectric nanopowder of claim 9 in the preparation of piezoelectric devices.

Technical Field

The invention belongs to the technical field of piezoelectric material preparation, and particularly relates to samarium-doped PZT piezoelectric nano powder and a preparation method and application thereof.

Background

Lead zirconate titanate (PZT) material is a piezoelectric functional material with wide application, has the advantages of good piezoelectric, dielectric and ferroelectric properties, easy doping modification, good stability and the like, particularly has higher piezoelectric constant and electromechanical coupling coefficient near a quasi-same phase boundary point, is a basic material for preparing devices such as an ultrasonic transducer, a piezoelectric transformer, a filter, a piezoelectric buzzer and the like, and has important position in the electronic material and mechanical manufacturing industry.

The existing rare earth element doped PZT material has more preparation processes by a solid phase sintering method and more complex process route; in the preparation process, the raw materials are sintered for 2 times at high temperature of about 1200-1350 ℃, the reaction conditions are harsh, the volatilization of Pb element is difficult to avoid, the component loss is easy to cause, and the deviation from the stoichiometric ratio is caused; the prepared ceramic powder is ground and ball-milled, the energy consumption and the time consumption are high, the particle size of the obtained powder is generally several microns, the prior art needs to be improved, and the nano powder without loss of components is prepared under a mild condition; the existing solid-phase sintering method has the disadvantages of complex process, long period, time consumption and energy consumption; the method can cause the intragranular diffusion of rare earth elements, cause the segregation at the surface crystal boundary, cause the aggregation of local elements, and is not easy to form enhanced local structure disorder, so that the microstructure and the electrical property of the ceramic are rapidly deteriorated.

The powder prepared by the hydrothermal method has the advantages of high purity, uniform components, superfine property, good dispersibility, high sintering activity and the like, and the size distribution of crystal grains is narrow, and the size and the shape are controllable. However, the hydrothermal synthesis process is a chemical reaction in a wet environment, the particle surface is wet, and hard agglomeration is easily caused during drying and crystallization, so that the powder particles are large. Patent CN 102718484 a discloses a method for preparing lead zirconate titanate piezoelectric ceramics, which can control the microstructure of ceramic powder crystal by precisely selecting appropriate hydrothermal conditions such as mineralizer concentration and reaction temperature, thereby greatly improving the powder sintering activity of the prepared lead zirconate titanate ceramics, and further improving the comprehensive performance of the fired piezoelectric ceramics. However, after sintering, the particles were significantly agglomerated and had a particle size of 10 μm. At present, most researches adopt PAA (acrylic resin), PVA (polyvinyl alcohol) or two surfactants to assist a hydrothermal method to promote dispersion and prepare PZT nanowires.

Disclosure of Invention

The invention aims to provide a preparation method of samarium-doped PZT piezoelectric ceramic. The invention adopts a hydrothermal doping process, and alkyl polyoxyethylene ether is added in the treatment process to prepare the samarium-doped PZT piezoelectric nano powder. The samarium-doped PZT piezoelectric nano powder has small particle size and higher piezoelectric performance, and can be effectively used as a piezoelectric device.

The invention also aims to provide samarium-doped PZT piezoelectric nano powder.

The invention also aims to provide the application of the samarium-doped PZT piezoelectric nano powder in the preparation of a piezoelectric device.

In order to achieve the above object, the present invention provides the following technical solutions:

a preparation method of samarium-doped PZT piezoelectric nano powder comprises the following steps:

s1: mixing tetrabutyl titanate, a water-based wetting dispersant, a zirconium salt and a precipitator, and stirring the mixed solution to perform coprecipitation reaction;

s2: adding lead salt, alkyl polyoxyethylene ether, samarium salt and a mineralizer into a product obtained by the S1 coprecipitation reaction, stirring the mixed solution for mineralization reaction, then carrying out hydrothermal reaction, and drying to obtain the samarium-doped PZT piezoelectric nano powder;

wherein the molecular formula of the samarium-doped PZT piezoelectric nano powder is Pb_1-xSm_x(Zr_0.52Ti_0.48)O₃，0.01≤x≤0.05。

At present, most researches adopt PAA, PVA or two surfactants to assist a hydrothermal method to promote dispersion, but the adoption of the two surfactants can change the crystalline phase (perovskite structure) and the morphology (square) of PZT powder, and the regulation of the particle size and the promotion of the corresponding piezoelectric performance are not realized.

According to the research of the invention, when the PZT powder is prepared by a hydrothermal method, PEG (polyethylene glycol) is added in the step S2, the crystal phase perovskite structure and the square shape of the prepared PZT powder are not changed, the particle size is not obviously changed, the agglomeration phenomenon is still generated, and the piezoelectric property is not obviously improved compared with the property of pure PZT ceramic; when the alkyl polyoxyethylene ether is adopted, on the basis that the perovskite structure crystalline phase structure and the square shape of PZT are not changed, a layer of thin organic diaphragm is formed on the surface of the crystal, so that hard agglomeration among particles is avoided, the powder particles are refined, and the particle size of the prepared powder can be effectively controlled so as to improve the piezoelectric performance of the powder.

In addition, rare earth element samarium is doped in the PZT powder. Researches show that the segregation characteristic of samarium in the crystal growth process can optimize the uniformity of crystal performance; the samarium is doped to form a solid solution, and the high-temperature calcination changes the growth behavior of crystal grains and the element distribution at the crystal boundary, and forms an enhanced local structure disorder and an engineering domain structure. When polarization is carried out, the relaxation polarization domain is enhanced, and the piezoelectric performance can be effectively improved.

According to the invention, a hydrothermal doping process is adopted, and under a relatively mild condition, the reaction of rare earth element samarium and PZT is realized, so that hydroxides of Pb, Zr and Ti are decomposed into oxides to form a solid solution; the doping synthesis under the high-temperature condition is avoided, the material composition of the obtained powder is the same as the designed composition, and no element content is lost; in addition, alkyl polyoxyethylene ether is added in the hydrothermal synthesis process, so that the prepared samarium-doped PZT piezoelectric nano powder has small particle size, uniform crystal distribution, excellent piezoelectric performance and piezoelectric constant d₃₃Can be as high as 510 pC/N.

Preferably, the zirconium salt is at least one of zirconyl nitrate or zirconium oxychloride.

Preferably, the lead salt is lead nitrate.

Preferably, the samarium salt is samarium nitrate.

Preferably, the aqueous wetting dispersant in S1 is polyethylene glycol.

Preferably, the precipitant in S1 is ammonia water.

Further preferably, the concentration of the precipitant in S1 is 0.1 to 0.5 mol/L.

Preferably, the specific steps of the coprecipitation reaction in S1 are: tetrabutyl titanate, a water-based wetting dispersant, a zirconium salt and a precipitator are mixed, the pH value of the solution is adjusted to 7-10 by the precipitator, and the reaction lasts for 1.0-2.5 h.

Preferably, the mass ratio of the alkyl polyoxyethylene ether to the lead salt in S2 is 1000: 1-5.

Further preferably, the mass ratio of the alkyl polyoxyethylene ether to the lead salt in S2 is 1000: 2.

Preferably, the specific steps of S2 are: adding lead salt and alkyl polyoxyethylene ether into the precipitate obtained in S1 in sequence, stirring uniformly, adding samarium salt, dropwise adding a mineralizer, and stirring for mineralization reaction; then carrying out hydrothermal reaction to obtain the samarium-doped PZT piezoelectric nano powder.

Preferably, the mineralizer in S2 is KOH.

Further preferably, the concentration of the mineralizer in S2 is 2.5-6 mol/L.

Preferably, the specific steps of the mineralization reaction in S2 are: adding mineralizer to regulate the pH value of the mixed solution to 10-12, and then stirring and reacting for 20-60 min.

Preferably, the temperature of the hydrothermal reaction in S2 is 180-220 ℃, and the reaction time is 10-15 h.

The invention also provides samarium-doped PZT piezoelectric nano powder prepared by the preparation method.

The application of the samarium-doped PZT piezoelectric nano powder in the preparation of piezoelectric devices is also within the protection scope of the invention.

Preferably, the samarium-doped PZT piezoelectric nano powder has a perovskite structure in a crystalline phase, a square shape and 300-400 nm particle size distribution.

Compared with the prior art, the invention has the following beneficial effects:

(1) according to the preparation method, the samarium-doped PZT piezoelectric nano powder is prepared by a hydrothermal doping process and a surfactant alkyl polyoxyethylene ether, so that the particle size of the prepared material is effectively reduced, and the piezoelectric performance of the material is correspondingly improved; and the preparation method is simple and low in cost.

(2) The particle size of the samarium-doped PZT piezoelectric nano powder prepared by the invention is 300-400 nm, and the piezoelectric constant d33 is as high as 510 pC/N.

Drawings

FIG. 1 is XRD patterns of samples prepared in examples and comparative examples;

FIG. 2 is an SEM photograph of a sample of example 1;

fig. 3 is an SEM image of the sample in comparative example 1.

Detailed Description

The invention is further illustrated by the following examples. These examples are intended to illustrate the invention and are not intended to limit the scope of the invention. Experimental procedures without specific conditions noted in the examples below, generally according to conditions conventional in the art or as suggested by the manufacturer; the raw materials, reagents and the like used are, unless otherwise specified, those commercially available from the conventional markets and the like.

Example 1

The embodiment provides samarium-doped PZT piezoelectric nano powder, and a preparation method thereof comprises the following steps:

s1: according to the formula Pb_1-xSm_x(Zr_0.52Ti_0.48)O₃Design, wherein x is 0.01. 5.2065g of tetrabutyl titanate is accurately weighed in a beaker, 30mL of absolute ethanol is added to be completely dissolved, 0.2g of PEG200 is added, 6.2377g of zirconium oxychloride octahydrate is accurately weighed in an ethanol solution of the tetrabutyl titanate, 30mL of deionized water is added, the materials are stirred together for 30min and uniformly mixed, 0.2mol/L of ammonia water solution is added dropwise, the pH value is adjusted to 9, and the stirring, the coprecipitation and the reaction are carried out for 2 h.

S2: and (3) carrying out suction filtration on the solution, washing for multiple times until the filtrate is neutral, carefully transferring the filter residue into a beaker, washing the filter residue on the filter paper, transferring the filter residue and the filter residue into the beaker together, and carrying out magnetic stirring to completely disperse the filter residue. 10.1880g of lead nitrate is accurately weighed and added into a beaker, and is stirred and dissolved, 0.02g of alkyl polyoxyethylene ether is added, the mixture is stirred for 10min, 5mL of samarium nitrate solution with 0.06mol/L of C is added, 6.0mol/L of KOH solution is added dropwise, the pH value is adjusted to 11, and the mixture is stirred and reacted for 30 min.

S3: transferring all the prepared solution into a high-temperature reaction kettle, continuously reacting for 12h at 220 ℃, taking out and filtering after cooling to room temperature, washing to be neutral, and drying to obtain samarium-doped PZT piezoelectric nano powder with the molecular formula of Pb_0.99Sm_0.01(Zr_0.52Ti_0.48)O₃。

Example 2

The embodiment provides samarium-doped PZT piezoelectric nano powder, and a preparation method thereof comprises the following steps:

s1: according to the formula Pb_1-xSm_x(Zr_0.52Ti_0.48)O₃Design, wherein x is 0.02. 5.0675g of tetrabutyl titanate is accurately weighed in a beaker, 30mL of absolute ethanol is added to be completely dissolved, 0.2g of PEG200 is added, 6.3886g of zirconium oxychloride octahydrate is accurately weighed in an ethanol solution of tetrabutyl titanate, 30mL of deionized water is added, the materials are stirred together for 30min and uniformly mixed, 0.2mol/L of ammonia water solution is added dropwise, the pH value is adjusted to 9, and the stirring, the coprecipitation and the reaction are carried out for 2 h.

S2: and (3) carrying out suction filtration on the solution, washing for multiple times until the filtrate is neutral, carefully transferring the filter residue into a beaker, washing the filter residue on the filter paper, transferring the filter residue and the filter residue into the beaker together, and carrying out magnetic stirring to completely disperse the filter residue. 9.9972g of lead nitrate is accurately weighed and added into a beaker, and stirred to be dissolved, 0.02g of alkyl polyoxyethylene ether is added, the mixture is stirred for 10min, 10mL of 0.06mol/L samarium nitrate solution is added, 6.0mol/L KOH solution is added dropwise, the pH value is adjusted to 11, and the mixture is stirred and reacted for 30 min.

S3: transferring all the prepared solution into a high-temperature reaction kettle, continuously reacting for 12h at 220 ℃, taking out and filtering after cooling to room temperature, washing to be neutral, and drying to obtain samarium-doped PZT piezoelectric nano powder with the molecular formula of Pb_0.98Sm_0.02(Zr_0.52Ti_0.48)O₃。

Example 3

The embodiment provides samarium-doped PZT piezoelectric nano powder, and a preparation method thereof comprises the following steps:

s1: push buttonMolecular formula Pb_1-xSm_x(Zr_0.52Ti_0.48)O₃Design, wherein x is 0.03. 5.0821g of tetrabutyl titanate is accurately weighed in a beaker, 30mL of absolute ethanol is added to be completely dissolved, 0.2g of PEG200 is added, 6.4071g of zirconium oxychloride octahydrate is accurately weighed in an ethanol solution of tetrabutyl titanate, 30mL of deionized water is added, the materials are stirred together for 30min and uniformly mixed, 0.2mol/L of ammonia water solution is added dropwise, the pH value is adjusted to 9, and the stirring, the coprecipitation and the reaction are carried out for 2 h.

S2: and (3) carrying out suction filtration on the solution, washing for multiple times until the filtrate is neutral, carefully transferring the filter residue into a beaker, washing the filter residue on the filter paper, transferring the filter residue and the filter residue into the beaker together, and carrying out magnetic stirring to completely disperse the filter residue. 9.9952g of lead nitrate is accurately weighed and added into a beaker, and stirred to be dissolved, 0.02g of alkyl polyoxyethylene ether is added, the mixture is stirred for 10min, 15mL of 0.06mol/L samarium nitrate solution is added, 6.0mol/L KOH solution is added dropwise, the pH value is adjusted to 11, and the mixture is stirred and reacted for 30 min.

S3: transferring all the prepared solution into a high-temperature reaction kettle, continuously reacting for 12h at 220 ℃, taking out and filtering after cooling to room temperature, washing to be neutral, and drying to obtain samarium-doped PZT piezoelectric nano powder with the molecular formula of Pb_0.97Sm_0.03(Zr_0.52Ti_0.48)O₃。

Example 4

The embodiment provides samarium-doped PZT piezoelectric nano powder, and a preparation method thereof comprises the following steps:

s1: according to the formula Pb_1-xSm_x(Zr_0.52Ti_0.48)O₃Design, wherein x is 0.04. 5.0986g of tetrabutyl titanate is accurately weighed in a beaker, 30mL of absolute ethanol is added to be completely dissolved, 0.2g of PEG200 is added, 6.4278g of zirconium oxychloride octahydrate is accurately weighed in an ethanol solution of tetrabutyl titanate, 30mL of deionized water is added, the materials are stirred together for 30min and uniformly mixed, 0.2mol/L of ammonia water solution is added dropwise, the pH value is adjusted to 9, and the stirring, the coprecipitation and the reaction are carried out for 2 h.

S2: and (3) carrying out suction filtration on the solution, washing for multiple times until the filtrate is neutral, carefully transferring the filter residue into a beaker, washing the filter residue on the filter paper, transferring the filter residue and the filter residue into the beaker together, and carrying out magnetic stirring to completely disperse the filter residue. 9.9243g of lead nitrate is accurately weighed and added into a beaker, and stirred to be dissolved, 0.02g of alkyl polyoxyethylene ether is added, the mixture is stirred for 10min, 20mL of 0.06mol/L samarium nitrate solution is added, 6.0mol/L KOH solution is added dropwise, the pH value is adjusted to 11, and the mixture is stirred and reacted for 30 min.

S3: transferring all the prepared solution into a high-temperature reaction kettle, continuously reacting for 12h at 220 ℃, taking out and filtering after cooling to room temperature, washing to be neutral, and drying to obtain samarium-doped PZT piezoelectric nano powder with the molecular formula of Pb_0.96Sm_0.04(Zr_0.52Ti_0.48)O₃。

Comparative example 1

The comparative example provides samarium-doped PZT piezoelectric nano powder, and the preparation method comprises the following steps: the procedure of S2 was carried out in the same manner as in example 1 except that no alkyl polyoxyethylene ether was added.

Comparative example 2

The comparative example provides samarium-doped PZT piezoelectric nano powder, and the preparation method comprises the following steps: in the step S2, PEG200 was added in place of alkyl polyoxyethylene ether, and the rest of the procedure was the same as in example 1.

Comparative example 3

The comparative example provides pure PZT piezoelectric nano powder, and the preparation method comprises the following steps: no samarium nitrate solution was added in step S3, i.e., x ═ 0, and the remaining steps were identical to example 1.

Performance testing

The X-ray diffraction phase analysis results of the samples prepared in examples 1 to 4 and comparative examples 1 to 3 of the present invention are shown in FIG. 1. As can be seen from fig. 1, all of the samples prepared in examples and comparative examples were of a single perovskite phase PZT structure, and no other hetero-phase was present.

In order to evaluate the performance of the samples prepared in examples 1 to 4 and comparative examples 1 to 3 of the present invention, the particle size distribution was measured; 1.5g of the powder is respectively taken, pressed into a sheet in a mould under 10Mpa, then sintered into a ceramic sheet along with the furnace in a high-temperature furnace at 1250 ℃, both sides of the ceramic sheet are polished by sand paper, silver paste is sintered, and the piezoelectric constant of the sample is tested, and the result is shown in table 1.

TABLE 1 particle size distribution and piezoelectric Properties of examples and comparative examples

As can be seen from table 1, in examples 1 to 4, the particle size of the prepared samarium-doped PZT powder was decreased with increasing amounts of samarium, the piezoelectric performance was increased and then decreased, and the piezoelectric constant reached the maximum value when x was 0.02.

Comparing comparative example 1 with example 1, and as can be seen from the SEM images of FIG. 2 and FIG. 3, the surfactant alkyl polyoxyethylene ether is added in example 1, the particle size distribution d50 of the obtained powder is 0.391 μm, the particle profile is clear, the size is uniform, and the powder is a distinct square crystal; the piezoelectric constant d33 is 413 pC/N. In contrast, in comparative example 1, no surfactant was added, the particle size distribution was increased to 3.594 μm, and the prepared powder was agglomerated severely, similarly to a block, the square profile of the crystal could not be seen significantly, and the piezoelectric constant was significantly reduced, as the piezoelectric constant d33 was reduced to 194 pC/N. The method shows that the agglomeration phenomenon of PZT particles is obviously improved by adding alkyl polyoxyethylene ether, and the piezoelectric property of the PZT particles is correspondingly improved.

In comparative example 2, the surfactant PEG200 was added in step S2, and the particle size of the obtained powder was not much different from that of the powder obtained in comparative example 1; the corresponding performance is not obviously improved.

In comparative example 3, the particle size distribution d50 increased by 1.3 times compared with example 1 without doping samarium, indicating that the piezoelectric properties (piezoelectric constant) of PZT piezoelectric ceramics can be effectively improved by doping samarium.

In conclusion, the samarium-doped PZT piezoelectric ceramic is prepared by adopting a hydrothermal method doping process and adding alkyl polyoxyethylene ether, wherein the d (50) of the samarium-doped PZT piezoelectric ceramic can be reduced to 0.332 mu m; and the piezoelectric property of the prepared piezoelectric ceramic is improved, d₃₃Can be as high as 510 pC/N. Shows the synergistic effect of rare earth element doping and alkyl polyoxyethylene ether, effectively reduces the particle size of the powder and correspondingly improves the materialThe piezoelectric properties of the material make it useful as a piezoelectric device.

The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.