60 results about "Samarium oxide" patented technology

The invention relates to the technical field of electronic glass fiber materials, and particularly discloses a corrosion-resistant low-dielectric glass fiber and a preparation process thereof. A preparation process of corrosion-resistant low-dielectric glass fibers comprises the following steps: S1, uniformly mixing glass fiber raw materials, melting, clarifying, homogenizing, cooling, and carrying out wiredrawing treatment to obtain glass fiber precursors; and S2, sequentially carrying out plasma treatment and impregnating compound treatment on the glass fiber precursor, drying and curing to obtain the corrosion-resistant low-dielectric glass fiber, silicon dioxide, aluminum oxide, magnesium oxide, boric oxide, calcium fluoride, tin oxide, sodium oxide, potassium oxide and rare earth oxide are used as glass fiber raw materials, and the rare earth oxide is a mixture of gadolinium oxide, cerium oxide and samarium oxide. The obtained glass fiber has excellent low dielectric property and corrosion resistance, and has a wide market prospect.

The invention belongs to the technical field of batteries, and provides a modified high-nickel ternary positive electrode material and a preparation method and application thereof, the modified high-nickel ternary positive electrode material comprises an inner core and a coating layer coating the inner core; the inner core comprises a gradient-doped high-nickel ternary material, a doped element comprises a samarium element, and the doping concentration of the samarium element is gradually increased from the center of the inner core to the surface of the inner core; the coating layer comprises a carbon layer, and samarium oxide particles are dispersed in the carbon layer. By forming gradient doping of the metal element samarium and utilizing 4f orbital electrons of Sm < 3 + >, H2-H3 phase change of the high-nickel ternary material can be inhibited, the layered structure of the material can be stabilized, lattice defects can be introduced, Li < + > transmission can be promoted, and diffusion energy barriers can be reduced. Meanwhile, the carbon layer doped with the samarium oxide particles is adopted for coating, on one hand, electrolyte corrosion is effectively inhibited, and on the other hand, the samarium oxide particles can further stabilize lattice oxygen and enhance electron conduction.

A composite electromagnetic wave-absorbing material and preparation method therefor are provided. The composite electromagnetic wave-absorbing material includes following raw materials: magnetite powder, nickel powder, copper powder, samarium oxide, gadolinium oxide, cerium oxide, carbon black powder, graphite powder, epoxy resin, barium titanate powder, antioxidant, curing agent, diluent and leveling agent. Ferrite wave-absorbing materials are used as matrixes to be compounded with nickel powder, copper powder, graphite powder, carbon black and barium titanate, and doped with mixed rare earth oxides through combination of samarium oxide, gadolinium oxide and cerium oxide to thereby obtain the composite electromagnetic wave-absorbing material which combines magnetic loss characteristics of magnetite powder, ferromagnetic behavior of nickel powder and conductivity of copper powder, helping to achieve good electromagnetic wave-absorbing performance. By introducing graphite powder, carbon black powder and barium titanate powder as fillers and doping rare earth, wave-absorbing characteristics of the composite electromagnetic wave-absorbing material are improved.

The application discloses a preparation method of a samarium trioxide doped lead zirconate titanate lead niobate piezoelectric fiber sensor. The application first prepares samarium trioxide doped lead zirconate titanate lead niobate ceramic; the ceramic is ground into powder and added into a sodium alginate solution, sodium dodecyl sulfate and citric acid are sequentially added, excessive water is added into the solution to obtain a low-viscosity slurry; then ball milling is carried out to break the agglomerates and obtain a uniform suspension, finally the slurry is injected into a CaCl2 solution to obtain a fiber, and the fiber is dried at room temperature and then calcined for the third time. The application precisely controls the molar ratio of raw materials, the reaction temperature, the reaction time and the doping ratio, guarantees the high-quality preparation of PNN-PZT / x Sm2O3 ceramic and fiberized piezoelectric ceramic, and makes the prepared piezoelectric fiber sensor have excellent piezoelectric performance and can more sensitively detect external signals.

Provided is an inorganic fiber or inorganic flake having excellent neutron shielding properties. A formulation composed of a base component in which SiO2 and Al2O3 are the main components (in which the total mass ratio of SiO2 and Al2O3 in the base component is 0.60 or more) and a neutron shielding component composed of at least one of gadolinium, gadolinium oxide, samarium, samarium oxide, cadmium, or cadmium oxide is prepared in a ratio of 50 to 90 parts by mass of the base component and 10 to 50 parts by mass of the neutron shielding component, and then melted, thereby obtaining a good amorphous inorganic fiber and inorganic flake.

An optical device includes, in sequence, a surface formed of a metal oxide, a samarium oxide-containing layer in contact with the surface formed of a metal oxide, and a magnesium fluoride-containing layer in contact with the samarium oxide-containing layer so as to suppress optical absorption resulting from high-rate sputter deposition of a magnesium fluoride-containing layer on a surface formed of a metal oxide.

The invention discloses nano samarium oxide dispersion strengthened NiCoCrAlY alloy powder and a preparation method thereof, and relates to the technical field of alloy powder preparation. The method specifically comprises the following steps that a NiCoCrAlY alloy bar is smelted, then heat preservation is conducted, and a liquid alloy melt is obtained; the liquid alloy melt is subjected to high-pressure inert gas atomization powder preparation, nano samarium oxide flow perpendicular to the liquid flow direction of the alloy melt is synchronously introduced in the powder preparation process, high-temperature alloy liquid drops formed during atomization are impacted and wrapped, and target powder is obtained; performing hot isostatic pressing on the target powder to obtain a target alloy bar; a target alloy bar is repeatedly subjected to multiple smelting, high-pressure inert gas atomization powder manufacturing and hot isostatic pressing treatment, an alloy bar is obtained, then the alloy bar is subjected to high-pressure inert gas atomization powder manufacturing, and the nanometer samarium oxide dispersion strengthening type NiCoCrAlY alloy powder is obtained. By adopting the preparation method disclosed by the invention, the nano samarium oxide dispersion strengthened NiCoCrAlY alloy powder with excellent morphology, nano samarium oxide dispersity and purity can be obtained.

The invention discloses a samarium-cobalt magnet and a preparation method thereof. The samarium-cobalt magnet takes low-melting-point alloy powder, samarium oxide powder and samarium-cobalt magnetic powder as raw materials; the component of the samarium cobalt magnetic powder is Sm (Co < 1-a-b-c > Fe Cu Zr < c >) < z >; the component of the low-melting-point alloy is RE1-xMx, RE is one or more of Pr, Nd and Sm, and M is one or more of Cu, Al and Ga. The preparation method comprises the following steps: smelting a samarium-cobalt alloy raw material and a low-melting-point alloy raw material, and sequentially performing coarse crushing, medium crushing and jet milling to obtain samarium-cobalt magnetic powder and low-melting-point alloy powder; mixing samarium oxide powder, low-melting-point alloy powder and samarium cobalt magnetic powder to obtain magnetic powder; sequentially performing magnetic field forming, cold isostatic pressing and low-temperature sintering to obtain a sintered blank; and the sintered blank is sequentially subjected to solution treatment and aging heat treatment. The bending strength and the fracture toughness of the samarium-cobalt magnet are greatly improved, and the samarium-cobalt magnet has high magnetic performance and good mechanical performance.

A rare-earth-doped aluminum-based composite material for shielding spent nuclear fuel comprises, by weight percentage: gadolinium oxide 1 wt.%–10 wt.%, europium oxide 1 wt.%–10 wt.%, samarium oxide 1 wt.%–10 wt.%, dysprosium oxide 1 wt.%–10 wt.%, erbium oxide 1 wt.%–10 wt.%, with the remainder being 6063 aluminum alloy powder. This invention exhibits excellent neutron absorption capacity. The aluminum-based material maintains both low weight and high strength and ductility. Furthermore, the addition of rare-earth elements such as Gd, Eu, and Sm, which have high thermal neutron absorption cross-sections, significantly enhances the material's neutron absorption capacity. The introduction of rare-earth elements such as Gd, which react with neutrons in an (n,γ) reaction, effectively prevents the formation of numerous helium bubbles in the matrix, thus improving the material's practical service life.

The application discloses an iron-based barium sodium niobate ceramic material with high energy storage performance and a preparation method thereof. 4‑2x Sm 2x Na2Fe x Nb 10‑x O 30 , wherein 1<=x<=1.25. Barium carbonate, samarium oxide, sodium carbonate, ferrous oxide and niobium pentoxide are used as raw materials, and a standard solid-phase method is adopted to sinter the iron-based barium sodium niobate ceramic material. In the product formula, iron is used to replace niobium in the barium sodium niobate, which is lead-free, environment-friendly, rich in iron reserves and low in price, and is beneficial to control the cost of raw materials. In addition, the iron replacement is beneficial to enhance the relaxor ferroelectric performance of the material, can obtain a more slender hysteresis loop, and improves the energy storage efficiency of the material. The prepared ceramic material has few pores and cracks, high density, and the microstructure is obviously improved, the grain size is more fine and uniform, the ferroelectric polarization intensity and the breakdown field strength are significantly improved, the problem that the barium sodium niobate material is difficult to sinter is solved, and the ferroelectric performance and the energy storage performance are significantly improved.

The invention discloses a samarium hydroxychloride nanosheet and a preparation method thereof, which belong to the technical field of preparation of rare earth element hydroxychloride nanomaterials. The samarium hydroxychloride material is composed of nanosheet-shaped samarium hydroxychloride, the thickness of the nanosheet is about 10-40nm, the side length is about 50-300nm, and the surface is smooth. The preparation method is as follows: pour samarium chloride hexahydrate and samarium oxide into a mortar, mix them thoroughly, grind them evenly, and then pour them into a reactor, set the temperature to 80-200℃, and set the time to 1-14h; after the reaction is completed, naturally cool to room temperature, grind the product again, and obtain white samarium hydroxychloride powder. The operation method of the invention is simple, easy to control, has good repeatability, high sample purity, and good crystallinity.

The invention discloses a wave-absorbing and wave-transmitting integrated soft magnetic material and a preparation method thereof. The preparation method comprises the following steps: S1, drying samarium oxide or nickel oxide, iron oxide, lithium carbonate, zinc oxide, manganese oxide, copper oxide or bismuth oxide, uniformly mixing, ball-milling, sieving, and carrying out magnetic field heat treatment to obtain a primary heat treatment product; and S2, performing heat treatment on the primary heat treatment product to obtain the wave-absorbing and wave-transmitting integrated soft magnetic material. The method is realized through an in-situ solid-phase sintering method in a magnetic field, and the material can absorb and transmit electromagnetic waves at the same time in combination with magnetic field heat treatment.

The application belongs to the technical field of high-entropy materials, and discloses a composite ceramic of Cr2O3-coated high-entropy pyrochlore and a preparation method and application thereof. 0.2 Nd 0.2 Sm 0.2 Gd 0.2 Sc 0.2 )2Zr2O7, wherein x is 5-20 wt.%; the composite ceramic is prepared by the following steps: sintering lanthanum oxide, neodymium oxide, samarium oxide, gadolinium oxide and zirconium oxide at 1400-1700 DEG C to obtain high-entropy pyrochlore powder, stirring the high-entropy pyrochlore powder in a CrCl3 solution after ball milling, drying to obtain CrCl3-coated high-entropy pyrochlore powder, cold sintering the CrCl3-coated high-entropy pyrochlore powder at 200-400 DEG C and 200-500 MPa, then heat preservation at 800-900 DEG C, and then pressureless sintering at 1500-1700 DEG C. The composite ceramic has high density, excellent radiation resistance and leaching resistance, and can be applied in the field of nuclear waste solidification.

The invention discloses a yttrium hydride-based high-temperature-resistant neutron moderation shielding material containing gadolinium oxide / samarium oxide / europium oxide and a preparation method and application thereof, and belongs to the technical field of nuclear radiation shielding. The problems that existing pure yttrium hydride is weak in neutron absorbing and shielding capacity, prone to cracking and pulverization and the like are solved. The density of the shielding material is 4.36-4.62 g / cm < 3 >, and the mass proportions of the substances in the total amount of YH3, Sm2O3, Eu2O3 and Gd2O3 are as follows: YH3 is more than or equal to 99% and less than 100%, Gd2O3 is more than or equal to 0% and less than or equal to 1%, Sm2O3 is more than or equal to 0% and less than or equal to 1%, Eu2O3 is more than or equal to 0% and less than or equal to 1%, Gd2O3 + Sm2O3 + Eu2O3 is more than 0% and less than or equal to 1%, and Gd2O3 + Sm2O3 + Eu2O3 is more than 0% and less than or equal to 1%. The material can effectively absorb full-spectrum neutrons, has high density, low crack rate and low defect rate, is resistant to high temperature and excellent in shielding performance, adopts hydrogenation, nano-ball milling and pressing sintering preparation processes, and is suitable for a micro nuclear power reactor at the temperature of 900 DEG C or below.

The application relates to the field of wear-resistant ceramic materials, in particular to a preparation method of a high-wear-resistant ceramic material for a gas valve plate, wherein ceramic powder is ball milled to obtain slurry, a binder composed of carboxymethyl cellulose and fatty acid modified nanocellulose and a sulfuric acid ester surfactant are added into the slurry, the ball milling is continuously carried out, spray granulation is carried out to obtain composite powder, the composite powder is pressed into a blank, and finally, the blank is sintered in an inert gas atmosphere, the ceramic material prepared by the method has excellent mechanical properties, and has good compression resistance, heat resistance, corrosion resistance and wear resistance; through comparison, it is found that the addition of zirconium oxide, samarium oxide, ytterbium oxide, carboxymethyl cellulose, fatty acid modified nanocellulose and sodium dodecyl sulfate has a positive effect on improving the various properties of the ceramic material.

The invention discloses a high-temperature SOFC electric pile double-layer electrolyte-cathode coating assembly and a preparation method thereof, and relates to the technical field of solid oxide fuel cells. The invention discloses a double-layer electrolyte-cathode coating assembly of a high-temperature SOFC (Solid Oxide Fuel Cell) electric pile. The double-layer electrolyte-cathode coating assembly comprises a double-layer electrolyte substrate and a cathode coating loaded on the double-layer electrolyte substrate, the cathode coating comprises the following components: cobalt-doped lanthanum gadolinate and nano-scale samarium oxide-doped cerium oxide; the double-layer electrolyte substrate comprises a scandium oxide stabilized zirconia bottom layer and a nanoscale samarium oxide doped cerium oxide top layer. The LGC and the SDC are compounded to serve as the cathode coating, the interface reaction caused by Sr is avoided, meanwhile, the medium-temperature performance is optimized through the high conductivity of the ScSZ in the double-layer electrolyte and the interface buffering effect of the SDC, and the thermal expansion coefficients of the cathode coating and the double-layer electrolyte are highly matched.

This invention discloses a high-entropy / medium-entropy alloy oxide catalyst, its preparation method, and its application in ammonia synthesis. The high-entropy / medium-entropy alloy oxide catalyst comprises ruthenium (Ru) and / or cobalt (Co) as active components, a composite rare earth oxide of lanthanum oxide, cerium oxide, and samarium oxide as additives, and graphite carbon (GC) as a carrier. The active components and additives are all supported on the carrier. The catalyst achieves a higher ammonia synthesis rate than conventional Ru-based catalysts, and its lower Ru active metal content reduces catalyst preparation costs, thus offering potential industrial applications.

The invention provides a lithium manganese iron phosphate positive electrode material, a preparation method thereof and an electrochemical device. The preparation method comprises the following steps: mixing a manganese source, an iron source, a phosphorus source, a lithium source and a first carbon source, and grinding to obtain primary slurry; performing spray drying on the primary slurry to obtain first solid powder, and performing primary sintering on the first solid powder to obtain a base material; mixing the base material, a second carbon source and a samarium source, and grinding to obtain secondary slurry; and carrying out spray drying on the secondary slurry to obtain second solid powder, and carrying out primary sintering on the second solid powder to form a coating layer on the surface of the matrix material, the coating layer comprising a carbon coating layer located on the surface of the matrix material and a samarium oxide coating layer located on one side, far away from the matrix material, of the carbon coating layer, so as to obtain the lithium manganese iron phosphate positive electrode material. The preparation method can effectively relieve voltage platform attenuation of the lithium iron manganese phosphate positive electrode material at high temperature, and effectively improves the structural stability and electrochemical stability of the lithium iron manganese phosphate positive electrode material.

The invention provides a supported catalyst for sodium hypochlorite catalytic oxidation and a preparation method thereof, and relates to the field of catalytic materials and sewage treatment, the catalyst takes gamma-Al2O3 microspheres as a carrier, oxides of Co and Cu as main catalytic active components, and Sm oxide as a cocatalyst, and the catalyst is prepared by a hydrothermal method. The main active component and the cocatalyst are loaded by dipping and calcining methods. The prepared catalyst can efficiently catalyze and degrade organic pollutants in water, compared with the prior art, the catalyst system adopts the ternary metal oxide, the catalytic performance of active components can be improved through the synergistic effect of cobalt oxide and copper oxide, the stability of the catalyst is also improved, and the catalytic performance of the catalyst is improved. And samarium oxide as a cocatalyst can improve the dispersibility of the active component, increase the specific surface area, promote the decomposition of sodium hypochlorite to generate active oxygen atoms, and improve the catalytic activity and the removal efficiency of refractory organic matters.

The invention belongs to the technical field of preparation of ceramic frits, and particularly relates to a high-whiteness ceramic frit and a preparation method thereof. The high-whiteness ceramic frit is prepared from the following raw materials: quartz, calcined aluminum oxide, lithium china clay ore, magnesium slag, cordierite powder, lanthanum silicate, strontium tetraborate, sodium fluosilicate, nano sodium zirconium phosphate, nano yttrium aluminate and nano samarium oxide. In the high-whiteness ceramic frit provided by the invention, quartz and calcined alumina form a continuous aluminosilicate glass phase three-dimensional network structure; the lithium china clay ore, the magnesium slag, the strontium tetraborate and the sodium fluosilicate have a synergistic effect and are filled in pores of a three-dimensional network structure to promote densification of ceramic frits, so that whiteness scattering and mechanical property degradation caused by the pores are avoided; the mechanical property of the ceramic frit is ensured by introducing cordierite powder and lanthanum silicate; nano sodium zirconium phosphate, nano yttrium aluminate and nano samarium oxide are added as functional fillers, so that the whiteness of the ceramic frit is further improved.

The present invention discloses a copper-samarium biphasic catalyst for the efficient electroreduction of carbon dioxide to synthesize multi-carbon products and a preparation method thereof. The samarium biphasic catalyst is a composite material of copper oxide and copper-samarium oxide, and the copper-samarium oxide is an oxide with a copper-samarium molar ratio of 1 or 0.5 or a mixture of the two; in the copper-samarium biphasic catalyst, the molar ratio of copper to samarium is not greater than 39. The copper-samarium biphasic catalyst of the present invention can be used for the electrocatalytic reduction of carbon dioxide to prepare multi-carbon products, wherein the copper-samarium biphasic catalyst is used as a cathode material to promote carbon-carbon coupling and improve the selectivity of multi-carbon products. The present invention designs a copper-samarium biphasic catalytic material, and by introducing a second metal samarium, regulates the interaction between metal and metal, metal and carrier, and metal and reaction intermediate in the catalyst, thereby improving the reaction activity and target product selectivity.

The invention provides a preparation method of samarium-iron-nitrogen magnetic powder, which comprises the following steps: mixing iron, samarium oxide and rare earth hydride (as a reducing agent, preferably lanthanum hydride and / or cerium hydride), performing ball milling treatment, and performing briquetting treatment on the obtained mixed material to obtain a green body; performing vacuum heat treatment on the green body to obtain a coarse samarium ferromagnetic powder material; crushing the coarse samarium-iron magnetic powder material, placing the crushed coarse samarium-iron magnetic powder material in an ammonia atmosphere, and carrying out high-temperature nitriding treatment to obtain coarse samarium-iron-nitrogen magnetic powder; and transferring the crude samarium-iron-nitrogen magnetic powder into a washing solution for cleaning treatment so as to remove residual non-magnetic impurities in a solid phase, thereby obtaining the samarium-iron-nitrogen magnetic powder, the preparation method for preparing the samarium-iron-nitrogen magnetic powder has the advantages of being small in reducing agent dosage, low in heat treatment temperature, short in time and the like, and the preparation cost of the samarium-iron-nitrogen magnetic powder is effectively reduced.

Method for producing a resistive particle sensor (1) for detecting particles in a gas stream, wherein the particle sensor (1) comprises an electrode system (2) of at least two electrodes (3, 4) and at least one semiconducting material (5), wherein the semiconducting material (5) contacts the electrodes (3, 4), wherein the semiconducting material (5) is at least one oxide selected from the group consisting of rare-earth-rare-earth mixed oxides, rare-earth-zirconium mixed oxides, alkaline-earth-zirconium mixed oxides, transition-metal-zirconium mixed oxides, rare-earth-aluminum mixed oxides, alkaline-earth-aluminum mixed oxides, transition-metal-aluminum mixed oxides, rare-earth-titanium mixed oxides, barium-titanium mixed oxides, transition-metal-titanium mixed oxides, rare-earth-indium mixed oxides, Alkaline earth indium mixed oxides, transition metal indium mixed oxides, rare earth zinc mixed oxides, alkaline earth zinc mixed oxides, transition metal zinc oxide mixed oxides, samarium oxide, yttrium oxideTerbium oxide and / or mixtures thereof, comprising, wherein a voltage is applied to the electrodes (3, 4) and the semiconducting material (5) under an atmosphere free of oxidizing and / or reducing agents, the voltage being selected such that at least one metal of the semiconducting material (5) is at least partially reduced or oxidized in the regions of the semiconducting material (5) which contact the electrodes (3, 4), characterized in that both electrodes (3, 4) are connected simultaneously at the same potential relative to the semiconducting material (5).

The invention provides a wide-temperature-range high-temperature thermistor material based on multi-principal-element design and a preparation method thereof.The wide-temperature-range high-temperature thermistor material is prepared from barium carbonate, lanthanum trioxide, neodymium oxide, samarium oxide, europium oxide, gadolinium oxide and titanium dioxide through mixing, grinding, calcining, cold isostatic pressing and high-temperature sintering. The material constant is B400 DEG C / 1000 DEG C = 11319K-17800K, the resistivity at the temperature of 400 DEG C is 2.36 * 10 < 6 > omegacm to 3.75 * 10 < 8 > omegacm, and the sensitivity coefficient at the temperature of 1000 DEG C is-0.70% / K to-1.10% / K. The multi-principal-element wide-temperature-range high-temperature thermistor material prepared by the method is stable in performance and good in consistency, and the series of thermistor materials have obvious negative temperature coefficient characteristics in the temperature range of 400-1150 DEG C and are expected to be used for preparing high-temperature thermistors.

The application discloses a preparation method of a rare earth modified oxide taking copper-aluminum hydrotalcite as a precursor, and belongs to the technical field of catalytic material preparation. In the preparation method, rare earth elements are simply introduced to be anchored on the copper-aluminum hydrotalcite layer plate, and the obtained samarium modified copper-aluminum oxide catalyst in-situ forms a samarium oxide coated copper nanoparticle structure through metal-support strong interaction in a methanol steam reforming reaction. The rare earth modified catalyst has better methanol steam reforming reaction activity and better stability than the unmodified copper-aluminum catalyst.

The invention belongs to the technical field of nuclear radiation shielding materials, and discloses a lead-free nuclear radiation shielding composite material and a preparation method thereof. The preparation method comprises the following steps: taking a mixture of samarium oxide, europium oxide, gadolinium oxide, tungsten oxide, bismuth oxide and boric oxide as an inner core, carrying out first coating on the inner core through an atomic layer deposition method, adding a silane coupling agent for second coating, mixing with polyethylene, and carrying out hot pressing to obtain the lead-free nuclear radiation shielding composite material. The neutron shielding performance and the gamma ray shielding performance are effectively improved through the materials of the inner core and the coating layer, and dual shielding of neutrons and gamma rays is achieved. The shielding powder of the inner core is coated, so that the dispersity of the powder and the compatibility with polyethylene are improved, and the mechanical property of the prepared composite material is improved.

The application discloses a high-temperature piezoelectric ceramic material, a preparation method and application, and belongs to the high-temperature piezoelectric ceramic material field. The application provides a high-temperature piezoelectric ceramic material, which is a samarium oxide doped lead ytterbium niobate-lead titanate piezoelectric ceramic material. The material is prepared by doping Sm2O3 in a lead ytterbium niobate-lead titanate binary system, and has high Curie temperature and further improved piezoelectric performance. Meanwhile, compared with existing ceramics, the piezoelectric performance of the ceramic at high temperature is more excellent. The application provides a preparation method of the high-temperature piezoelectric ceramic material, which can avoid the occurrence of a second phase in the ceramic, successfully realize stable sintering of the PYN-PT based material, and the ceramic prepared by the method has uniform particle size and high density. The preparation method has the advantages of simple process, low sintering temperature, low cost and suitability for large-scale industrial production, and has a wide application prospect in the field of high-temperature piezoelectric materials and devices.

The embodiment of the invention provides a samarium-iron-nitrogen magnetic material and a preparation method and application thereof.The samarium-iron-nitrogen magnetic material comprises samarium-iron-nitrogen particles and samarium oxide particles, at least part of the samarium oxide particles are free among the samarium-iron-nitrogen particles, the average mass content of oxygen in the surface layers of the samarium-iron-nitrogen particles is smaller than or equal to 3.6%, and the average mass content of the samarium oxide particles is smaller than or equal to 3.6%. The surface layer is an area of the samarium-iron-nitrogen particles with the radius depth of 100nm from the surface to the inside. The oxidation degree of the samarium-iron-nitrogen particles in the samarium-iron-nitrogen magnetic material is low, the magnetic performance and stability are improved, and the free samarium oxide particles have a dispersion strengthening effect and can generate a grading effect with the samarium-iron-nitrogen particles; when the samarium-iron-nitrogen magnetic material is used for preparing a magnet, the filling rate of the magnetic material in the magnet can be increased, and the magnetic properties and mechanical properties such as residual magnetism, coercive force and magnetic energy product of the magnet are enhanced.

The invention belongs to the technical field of rare earth permanent magnet materials, and discloses a method for improving the phase purity of SmFe12-based permanent magnet powder. According to the method, carbonyl iron, cobalt powder, samarium oxide and titanium dioxide are used as main raw materials, metal calcium particles are used as a reducing agent, auxiliaries are added, ball milling is carried out under the protective atmosphere, then segmented sintering is carried out, water washing, acid pickling and isopropanol cleaning are carried out after sintering is finished, and the high-purity SmFe12-based permanent magnet powder is obtained. By adjusting the Ca / O molar ratio of the reducing agent to the raw materials, the reduction rate of the oxide and the diffusion rate of Sm atoms in the diffusion process are controlled; and a segmented sintering process is combined, so that the oxide is fully reduced, a 1: 12 phase is formed at the optimal temperature, and the purity of the magnetic powder is improved. And ball milling is carried out before sintering, and the raw materials are uniformly mixed and levigated, so that reduction diffusion is better carried out.

The invention discloses a catalyst for preparing ketene through selective hydrogenation of diketene as well as a preparation method and application of the catalyst. The catalyst comprises an active component, a carrier and a modification aid, the active components are primary metal ruthenium and secondary metal palladium; the carrier is one of erbium oxide and samarium oxide; the modification auxiliary agent is one of mercaptoamines. When the catalyst is applied to preparation of ketene through selective hydrogenation of diketene, the conversion rate and selectivity are high, the reaction conditions are mild, the hydrogen pressure is lower, and the catalyst is suitable for industrial production.