阅读说明：本技术 一种制备纳米镧锶锰氧化物粉体的方法 (Method for preparing nano lanthanum strontium manganese oxide powder ) 是由 曾珧法 白平平 童培云 任晓东 于 2021-01-22 设计创作，主要内容包括：本发明揭示了一种制备纳米镧锶锰氧化物粉体的方法,包括以下步骤：向混料桶中加入纯水,随后向混料桶中加入分散剂并搅拌,再向混料桶中加入氧化镧、碳酸锶和二氧化锰并球磨后得到第一混合浆料；向第一混合浆料中加入粘结剂,并持续搅拌后得到第二混合浆料；使用喷雾干燥机将第二混合浆料进行喷雾干燥得到第一中间粉体；将第一中间粉体置于真空脱脂烧结炉内煅烧并进行恒温恒压后得到第二中间粉体；将第二中间粉体继续煅烧并进行恒温恒压后得到第三中间粉体；将第三中间粉体继续煅烧并进行恒温恒压后得到第四中间粉体；将第四中间粉体置于超声波振动筛分机内震碎并筛分后得到纳米镧锶锰氧化物粉体,本发明能制备粒径均匀的纳米镧锶锰氧化物粉体。(The invention discloses a method for preparing nano lanthanum strontium manganese oxide powder, which comprises the following steps: adding pure water into a mixing barrel, then adding a dispersing agent into the mixing barrel, stirring, adding lanthanum oxide, strontium carbonate and manganese dioxide into the mixing barrel, and performing ball milling to obtain first mixed slurry; adding a binder into the first mixed slurry, and continuously stirring to obtain second mixed slurry; spray drying the second mixed slurry by using a spray dryer to obtain first intermediate powder; placing the first intermediate powder in a vacuum degreasing sintering furnace for calcining and carrying out constant temperature and constant pressure to obtain second intermediate powder; continuously calcining the second intermediate powder and carrying out constant temperature and constant pressure to obtain third intermediate powder; continuously calcining the third intermediate powder and carrying out constant temperature and constant pressure to obtain fourth intermediate powder; and placing the fourth intermediate powder in an ultrasonic vibration screening machine to shake and break and screen to obtain the nano lanthanum strontium manganese oxide powder.)

1. A method for preparing nano lanthanum strontium manganese oxide powder is characterized in that the molecular formula of the powder is La_{1- x}Sr_xMnO₃Wherein x is more than or equal to 0.1 and less than or equal to 0.4, and the preparation steps are as follows:

s1, preparing pure water, a dispersing agent, a binder, lanthanum oxide, strontium carbonate and manganese dioxide with certain mass;

s2, adding pure water into a mixing barrel, then adding a dispersing agent into the mixing barrel, stirring for 10-20 min, then adding lanthanum oxide, strontium carbonate and manganese dioxide into the mixing barrel, and ball-milling for 240-300 min to obtain first mixed slurry;

s3, adding a binder into the first mixed slurry, and continuously stirring for 30-40 min to obtain second mixed slurry;

s4, spray drying the second mixed slurry by using a spray dryer to obtain first intermediate powder;

s5, placing the first intermediate powder in a vacuum degreasing sintering furnace, calcining for 180-240 min to 400-600 ℃, and then carrying out constant temperature and pressure for 120-180 min to obtain second intermediate powder;

s6, continuously calcining the second intermediate powder for 120-180 min until the temperature is 800-1000 ℃, and then carrying out constant temperature and pressure for 120-180 min to obtain third intermediate powder;

s7, continuously calcining the third intermediate powder for 120-180 min until the temperature is 1100-1300 ℃, and then carrying out constant temperature and pressure for 120-180 min to obtain fourth intermediate powder;

and S8, placing the fourth intermediate powder in an ultrasonic vibration screening machine to be vibrated and crushed and screening to obtain the nano lanthanum strontium manganese oxide powder.

2. The method for preparing nano lanthanum strontium manganese oxide powder according to claim 1, wherein the molar ratio of lanthanum oxide, strontium carbonate and manganese dioxide is (0.75-4.5): 1 (2.5-10).

3. The method for preparing nano lanthanum strontium manganese oxide powder according to claim 1, wherein in the spray drying process, the inlet temperature of hot air of a spray dryer is 200-220 ℃, the outlet temperature is 100-125 ℃, the rotation speed of an atomizer of a spray drying tower is 10000-20000 rpm, and the rotation speed of a peristaltic pump is 100-180 rpm.

4. The method of claim 2, wherein the frequency of the ultrasonic vibration screening machine is set to 15KHz to 18KHz during the screening process, and the screened mesh is 1340 mesh.

5. The method of claim 1, wherein the first mixed slurry has a particle size of 0.1-2 μm.

6. The method for preparing nano lanthanum strontium manganese oxide powder according to claim 1, wherein the mass of the dispersant is 2-3% of the total mass of lanthanum oxide, strontium carbonate and manganese dioxide, and the mass of the binder is 5-8% of the total mass of lanthanum oxide, strontium carbonate and manganese dioxide.

7. The method of claim 1, wherein the dispersant is one of triethylhexylphosphoric acid, sodium dodecylsulfate, a cellulose derivative, hydroxymethyl cellulose, and sodium lignosulfonate.

8. The method of claim 1, wherein the binder is at least one of polyvinyl alcohol, polyethylene glycol, and polyvinyl acetate.

9. The method for preparing nano lanthanum strontium manganese oxide powder according to claim 1, wherein the mass of the pure water is 40-50% of the total mass of the pure water, lanthanum oxide, strontium carbonate and manganese dioxide.

10. The method for preparing nano lanthanum strontium manganese oxide powder according to claim 1, wherein the purity of lanthanum oxide is not less than 2.5N and the particle size is not more than 25 μm, the purity of strontium carbonate is not less than 2.5N and the particle size is not more than 25 μm, and the purity of lanthanum oxide is not less than 3N and the particle size is not more than 25 μm.

Technical Field

The invention relates to a preparation method of an oxide, in particular to a method for preparing nano lanthanum strontium manganese oxide powder.

Background

Lanthanum strontium manganese oxide (La)_1-xSr_xMnO₃) The material is a functional material with wide application, namely lanthanum strontium manganese oxide (La)_1-xSr_xMnO₃) The material has perovskite crystal phase structure, can be used as a magneto-resistance material, has great application prospect, and is applied to be made into magnetic heads, magneto-resistance memories, automobile sensors and the like in information storage systems at present. Lanthanum strontiumManganese oxide (La)_1-xSr_xMnO₃) The material can also be used as a magnetic refrigeration material, and the magnetic refrigeration material also has a great application prospect, and is widely applied to the industries of medical treatment and health, aerospace, automobile equipment and the like at present. Due to lanthanum strontium manganese oxide (La)_{1- x}Sr_xMnO₃) The material has unique properties, and has been widely applied to the fields of chemical industry, machinery, electronics and the like in recent years, while the La with the perovskite structure_1-xSr_xMnO₃Materials have attracted increasing attention in the physical and chemical fields because of their giant magnetoresistance properties and catalytic properties.

Preparation of La by the prior art_1-xSr_xMnO₃The powder method comprises the following steps:

(1) solid phase reaction method

Is a traditional powdering process, mainly uses pure La₂O₃、SrCO₃And MnO₂Weighing according to a certain stoichiometric ratio, adding zirconia balls for dry grinding, and then carrying out heat treatment. The solid phase method has simple process flow and is used for producing the conventional La_1-xSr_xMnO₃Industrial process of powder, but in order to mix the three raw materials evenly and reduce the particle size of the particles, the ball milling time is very long, and is more than 10 hours; and because the particle size of the particles is larger, the reaction time required by high-temperature calcination at the temperature of more than 1000 ℃ is more than 10 hours; produced La_1-xSr_xMnO₃The powder is easy to agglomerate, the particle size is larger, the particle size distribution is wide, and the satisfactory particle size is difficult to achieve; and a single-phase perovskite structure is not easily obtained.

(2) Sol-gel process

The sol-gel method is a method of hydrolyzing inorganic salt or metal alkoxide, then polymerizing and gelating solute, or adding a certain amount of organic acid as ligand into aqueous solution of metal inorganic salt, adjusting the pH value of the system with inorganic acid and alkali, slowly evaporating to obtain gel, drying and roasting the gel to obtain nano powder. For example with La (NO)₃)₃、Sr(NO₃)₂And Mn (NO)₃)₂Adding proper citric acid into the raw materials, and adjusting the system by ammonia waterAnd then the pH of the solution is obtained.

The method has the advantages of low reaction temperature, good uniformity of the synthesized powder and small particle size. But the production process is complex; the metal alkoxide is used as a raw material, so that the cost is high, and the alkoxide has high toxicity, is harmful to human health and is easy to cause environmental pollution; the carbon ligand in the organic ligand is not easy to remove under the non-oxide atmosphere, thereby increasing the content of impurities in the prepared powder.

Aiming at the defects in the prior art, the invention overcomes the technical problem and provides a method for preparing nano lanthanum strontium manganese oxide powder.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a method for preparing nano lanthanum strontium manganese oxide powder.

In order to achieve the purpose, the invention adopts the following technical scheme.

The invention provides a method for preparing nano lanthanum strontium manganese oxide powder, the molecular formula of the powder is La_{1- x}Sr_xMnO₃Wherein x is more than or equal to 0.1 and less than or equal to 0.4, and the preparation method comprises the following steps:

s1, preparing pure water, a dispersing agent, a binder, lanthanum oxide, strontium carbonate and manganese dioxide with certain mass;

s2, adding pure water into a mixing barrel, then adding a dispersing agent into the mixing barrel, stirring for 10-20 min, then adding lanthanum oxide, strontium carbonate and manganese dioxide into the mixing barrel, and ball-milling for 240-300 min to obtain first mixed slurry;

s3, adding a binder into the first mixed slurry, and continuously stirring for 30-40 min to obtain second mixed slurry;

s4, spray drying the second mixed slurry by using a spray dryer to obtain first intermediate powder;

s5, placing the first intermediate powder in a vacuum degreasing sintering furnace, calcining for 180-240 min until the temperature is 400-600 ℃, and then carrying out constant temperature and pressure for 120-180 min to obtain second intermediate powder;

s6, continuously calcining the second intermediate powder for 120-180 min to reach the temperature of 800-1000 ℃, and then carrying out constant temperature and pressure for 120-180 min to obtain third intermediate powder;

s7, continuously calcining the third intermediate powder for 120-180 min until the temperature is 1100-1300 ℃, and then carrying out constant temperature and pressure for 120-180 min to obtain fourth intermediate powder;

and S8, placing the fourth intermediate powder in an ultrasonic vibration screening machine to be vibrated and crushed and screening to obtain the nano lanthanum strontium manganese oxide powder.

According to a further improvement of the invention, the molar ratio of lanthanum oxide, strontium carbonate and manganese dioxide is (0.75-4.5) to 1 (2.5-10).

As a further improvement of the invention, in the spray drying process, the inlet temperature of hot air of the spray dryer is 200-220 ℃, the outlet temperature is 100-125 ℃, the rotating speed of an atomizer of a spray drying tower is 10000-20000 rpm, and the rotating speed of a peristaltic pump is 100-180 rpm.

As a further improvement of the invention, in the screening process, the frequency of the ultrasonic vibration screening machine is set to be 15 KHz-18 KHz, and the screened screen is 1340 meshes.

As a further improvement of the invention, the particle size of the first mixed slurry is 0.1-2 μm.

As a further improvement of the invention, the mass of the dispersing agent is 2-3% of the total mass of lanthanum oxide, strontium carbonate and manganese dioxide, and the mass of the binder is 5-8% of the total mass of lanthanum oxide, strontium carbonate and manganese dioxide.

As a further improvement of the invention, the dispersant is one of triethyl hexyl phosphoric acid, sodium dodecyl sulfate, cellulose derivatives, hydroxymethyl cellulose and sodium lignosulphonate.

As a further improvement of the invention, the binder is at least one of polyvinyl alcohol, polyethylene glycol and polyvinyl acetate.

As a further improvement of the invention, the mass of the pure water is 40-50% of the total mass of the pure water, the lanthanum oxide, the strontium carbonate and the manganese dioxide.

As a further improvement of the invention, the purity of lanthanum oxide is more than or equal to 2.5N and the grain diameter is less than or equal to 25 mu m, the purity of strontium carbonate is more than or equal to 2.5N and the grain diameter is less than or equal to 25 mu m, and the purity of lanthanum oxide is more than or equal to 3N and the grain diameter is less than or equal to 25 mu m.

The invention provides a method for preparing nanometer lanthanum strontium manganese oxide powder, which combines the advantages and disadvantages of a sol-gel method, wherein a small amount of dispersant and binder added in the preparation process are organic solvents, additives are completely volatilized in the sintering process, impurities are not introduced, acid or alkali is not used for adjusting pH in the preparation process, and the purity of the lanthanum strontium manganese oxide powder is not influenced.

Detailed Description

The technical solutions will be described clearly and completely in the following with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a method for preparing nano lanthanum strontium manganese oxide powder, the molecular formula of the powder is La_{1- x}Sr_xMnO₃Wherein x is more than or equal to 0.1 and less than or equal to 0.4, and the preparation method comprises the following steps:

s1, preparing pure water, a dispersing agent, a binding agent, lanthanum oxide, strontium carbonate and manganese dioxide with certain mass.

In some embodiments of the invention, the molar ratio of lanthanum oxide, strontium carbonate and manganese dioxide is (0.75-4.5): 1 (2.5-10), the purity of lanthanum oxide is more than or equal to 2.5N, and the particle size is less than or equal to 25 μm, the purity of strontium carbonate is more than or equal to 2.5N, and the particle size is less than or equal to 25 μm, and the purity of lanthanum oxide is more than or equal to 3N, and the particle size is less than or equal to 25 μm.

In some embodiments of the present invention, the dispersant is one of triethylhexylphosphoric acid, sodium lauryl sulfate, cellulose derivative, hydroxymethyl cellulose, and sodium lignosulfonate, and the binder is at least one of polyvinyl alcohol, polyethylene glycol, and polyvinyl acetate

In some embodiments of the invention, the dispersant is 2-3% by mass of the total mass of lanthanum oxide, strontium carbonate and manganese dioxide, and the binder is 5-8% by mass of the total mass of lanthanum oxide, strontium carbonate and manganese dioxide.

In some embodiments of the invention, the mass of the pure water is 40-50% of the total mass of the pure water, lanthanum oxide, strontium carbonate and manganese dioxide, so that the particles can be effectively bonded, the use amount of the pure water is reduced, the moisture of the powder can be quickly evaporated in the spray drying process, and the environment cannot be polluted.

S2, adding pure water into the mixing barrel, then adding the dispersing agent into the mixing barrel, stirring for 10-20 min, then adding lanthanum oxide, strontium carbonate and manganese dioxide into the mixing barrel, and ball-milling for 240-300 min to obtain first mixed slurry.

In some embodiments of the invention, the purpose of adding the dispersing agent into the mixing barrel and stirring for 10-20 min is to uniformly stir and disperse the dispersing agent, so that the subsequently added materials are prevented from agglomerating.

In some embodiments of the invention, lanthanum oxide, strontium carbonate and manganese dioxide with the particle size of less than or equal to 25 μm are added, and ball milling is carried out for 240-300 min to obtain a first mixed slurry with the particle size of 0.1-2 μm.

And S3, adding a binder into the first mixed slurry, and continuously stirring for 30-40 min to obtain a second mixed slurry.

In some embodiments of the invention, the second mixed slurry obtained after stirring for 30-40 min has a binder completely coating the lanthanum oxide, strontium carbonate and manganese dioxide powder.

And S4, spray-drying the second mixed slurry by using a spray dryer to obtain first intermediate powder.

In some embodiments of the present invention, during the spray drying process, the inlet temperature of the hot air of the spray dryer is 200 to 220 ℃, the outlet temperature is 100 to 125 ℃, the rotation speed of the atomizer of the spray drying tower is 10000 to 20000rpm, and the rotation speed of the peristaltic pump is 100 to 180 rpm.

S5, placing the first intermediate powder in a vacuum degreasing sintering furnace, calcining for 180-240 min until the temperature is 400-600 ℃, and then carrying out constant temperature and pressure for 120-180 min to obtain second intermediate powder.

In some embodiments of the invention, the first intermediate powder is heatedIntroducing circulating hot air to 400-600 ℃ to thermally decompose organic solvents such as a binder, a dispersing agent and the like among particles in the oxide particles, and finally discharging the organic solvents in a gas form, wherein the temperature is in a La temperature range₂O₃Absorbing heat to generate crystal transformation of SrCO₃Absorbing heat, loose structure and simultaneously reacting the two to generate La₂SrO₄。

And S6, continuously calcining the second intermediate powder for 120-180 min until the temperature is 800-1000 ℃, and then carrying out constant temperature and pressure for 120-180 min to obtain third intermediate powder.

In some embodiments of the invention, MnO is added in the environment of 800-1000 ℃ after the temperature of the second intermediate powder is raised to 800-1000 DEG C₂Will decompose into Mn₂O₃，Mn₂O₃Will follow La₂O₃LaMnO is generated in this temperature range₃，LaMnO₃And La₂SrO₄Formation of La_{( 1 - x )}Sr_xMnO₃。

And S7, continuously calcining the third intermediate powder for 120-180 min until the temperature is 1100-1300 ℃, and then carrying out constant temperature and pressure for 120-180 min to obtain fourth intermediate powder.

In some embodiments of the invention, the temperature of the third intermediate powder is finally raised to 1100-1300 ℃ to obtain La_{( 1 - x )}Sr_xMnO₃The crystal forms grow continuously.

And S8, placing the fourth intermediate powder in an ultrasonic vibration screening machine to be vibrated and crushed and screening to obtain the nano lanthanum strontium manganese oxide powder.

As a further improvement of the invention, in the screening process, the frequency of the ultrasonic vibration screening machine is set to be 15 KHz-18 KHz, and the screened screen is 1340 meshes.

For further understanding of the present invention, the method and effects of the present invention will be described in further detail with reference to specific examples. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

Example 1.

(1) Preparing 2.65 Kg of pure water, 0.133 Kg of hydroxymethyl cellulose as a dispersing agent, 0.53 Kg of polyethylene glycol as a binder, 2.932 Kg of lanthanum oxide with purity not less than 2.5N and particle size not more than 25 μm, 0.150 Kg of strontium carbonate with purity not less than 2.5N and particle size not more than 25 μm and 0.895 Kg of manganese dioxide with purity not less than 3N and particle size not more than 25 μm;

(2) adding pure water into a mixing barrel, then adding a dispersing agent into the mixing barrel, stirring for 10min, adding lanthanum oxide, strontium carbonate and manganese dioxide into the mixing barrel, and ball-milling for 240min to obtain first mixed slurry with the particle size D90 of 1.89 mu m;

(3) adding a binder into the first mixed slurry, and continuously stirring for 30 min to obtain a second mixed slurry;

(4) in the process of spray drying the second mixed slurry by using a spray dryer to obtain first intermediate powder, the inlet temperature of hot air of the spray dryer is 200 ℃, the outlet temperature of the hot air of the spray dryer is 100 ℃, the rotating speed of an atomizer of a spray drying tower is 10000 rpm, and the rotating speed of a peristaltic pump is 180 rpm;

(5) placing the first intermediate powder in a vacuum degreasing sintering furnace, calcining for 180 min to 400 ℃, and then carrying out constant temperature and pressure for 120 min to obtain second intermediate powder;

(6) continuously calcining the second intermediate powder for 120 min to reach the temperature of 800 ℃, and then carrying out constant temperature and pressure for 120 min to obtain third intermediate powder;

(7) continuously calcining the third intermediate powder for 180 min to 1100 ℃, and then carrying out constant temperature and pressure for 180 min to obtain fourth intermediate powder;

(8) placing the fourth intermediate powder in an ultrasonic vibration screening machine, setting the frequency of the ultrasonic vibration screening machine to be 15KHz, screening with a screen of 1340 meshes, vibrating, crushing and screening to obtain the powder with the theoretical chemical formula of La_0.9Sr_0.1MnO₃Lanthanum strontium manganese oxide powder.

The powder has an average particle diameter of 6.5 μm and a specific surface area of 7349 m²/Kg。

Example 2.

(1) Preparing 4.278 Kg of pure water, 0.256 Kg of hydroxymethyl cellulose as a dispersing agent, 0.428 Kg of polyvinyl alcohol as a binding agent, 2.444 Kg of lanthanum oxide with purity not less than 2.5N and particle size not more than 25 μm, 0.748 Kg of strontium carbonate with purity not less than 2.5N and particle size not more than 25 μm and 1.087 Kg of manganese dioxide with purity not less than 3N and particle size not more than 25 μm;

(2) adding pure water into a mixing barrel, then adding a dispersing agent into the mixing barrel, stirring for 20min, adding lanthanum oxide, strontium carbonate and manganese dioxide into the mixing barrel, and ball-milling for 300min to obtain first mixed slurry with the particle size D90 of 1.31 mu m;

(3) adding a binder into the first mixed slurry, and continuously stirring for 40min to obtain a second mixed slurry;

(4) in the spray drying process of obtaining the first intermediate powder by using a spray dryer to spray-dry the second mixed slurry, the inlet temperature of hot air of the spray dryer is 220 ℃, the outlet temperature is 125 ℃, the rotating speed of an atomizer of a spray drying tower is 20000rpm, and the rotating speed of a peristaltic pump is 100 rpm;

(5) placing the first intermediate powder in a vacuum degreasing sintering furnace, calcining for 240min to 600 ℃, and then carrying out constant temperature and pressure of 180 min to obtain second intermediate powder;

(6) continuously calcining the second intermediate powder for 180 min to reach the temperature of 1000 ℃, and then carrying out constant temperature and pressure for 180 min to obtain third intermediate powder;

(7) continuously calcining the third intermediate powder for 120 min to 1300 ℃, and then carrying out constant temperature and pressure for 120 min to obtain fourth intermediate powder;

(8) placing the fourth intermediate powder in an ultrasonic vibration screening machine, setting the frequency of the ultrasonic vibration screening machine to be 18KHz, screening with a screen of 1340 meshes, vibrating, crushing and screening to obtain the powder with the theoretical chemical formula of La_0.6Sr_0.4MnO₃Lanthanum strontium manganese oxide powder.

The powder has an average particle diameter of 2.3 μm and a specific surface area of 10357 m²/Kg。

Example 3.

(1) Preparing 3.485 Kg of pure water, 0.182 Kg of hydroxymethyl cellulose as a dispersant, 0.436 Kg of mixed solvent of polyvinyl alcohol and polyethylene glycol as a binder, 2.606 Kg of lanthanum oxide with purity not less than 2.5N and particle size not more than 25 μm, 0.299 Kg of strontium carbonate with purity not more than 2.5N and particle size not more than 25 μm and 0.869 Kg of manganese dioxide with purity not less than 3N and particle size not more than 25 μm;

(2) adding pure water into a mixing barrel, then adding a dispersing agent into the mixing barrel, stirring for 20min, adding lanthanum oxide, strontium carbonate and manganese dioxide into the mixing barrel, and ball-milling for 300min to obtain first mixed slurry with the particle size D90 of 1.46 mu m;

(3) adding a binder into the first mixed slurry, and continuously stirring for 35 min to obtain a second mixed slurry;

(4) in the process of spray drying the second mixed slurry by using a spray dryer to obtain first intermediate powder, the inlet temperature of hot air of the spray dryer is 210 ℃ and the outlet temperature of the hot air of the spray dryer is 110 ℃), the rotating speed of an atomizer of a spray drying tower is 18000 rpm, and the rotating speed of a peristaltic pump is 125 rpm;

(5) calcining the first intermediate powder in a vacuum degreasing sintering furnace for 240min to 470 ℃, and then carrying out constant temperature and pressure for 150 min to obtain second intermediate powder;

(6) continuously calcining the second intermediate powder for 150 min to reach the temperature of 950 ℃, and then carrying out constant temperature and pressure for 150 min to obtain third intermediate powder;

(7) continuously calcining the third intermediate powder for 150 min to 1150 ℃, and then carrying out constant temperature and pressure for 150 min to obtain fourth intermediate powder;

(8) placing the fourth intermediate powder in an ultrasonic vibration screening machine, setting the frequency of the ultrasonic vibration screening machine to be 18KHz, screening with a screen of 1340 meshes, vibrating, crushing and screening to obtain the powder with the theoretical chemical formula of La_0.8Sr_0.2MnO₃Lanthanum strontium manganese oxide powder.

The powder has an average particle diameter of 3.5 μm and a specific surface area of 11593 m²/Kg。

The invention provides a method for preparing nanometer lanthanum strontium manganese oxide powder, which combines the advantages and disadvantages of a sol-gel method, wherein a small amount of dispersant and binder added in the preparation process are organic solvents, additives are completely volatilized in the sintering process, impurities are not introduced, acid or alkali is not used for adjusting pH in the preparation process, and the purity of the lanthanum strontium manganese oxide powder is not influenced.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.