Disclosed are an R-T-B-based permanent magnet material, a preparation method therefor and the use thereof. The R-T-B-based permanent magnet material I comprises the following components: 29.0-32.5% of R including RH, 0.30 to 0.50 wt. % of Cu, 0.05 to 0.20 wt. % of Ti, 0.85 to 1.05 wt. % of B, 0.1 to 0.3 wt. % of C, 66 to 68 wt. % of Fe, wherein R is a rare earth element and R at least includes Nd; and RH is a heavy rare earth element and RH at least includes Tb or Dy, A Cu—Ti—C grain boundary phase is formed in the R-T-B-based permanent magnet material I, and Hcj is significantly improved.

The present invention involves a graphene-containing rare earth permanent magnet material and preparation method thereof. The graphene-containing rare earth permanent magnet material, comprising: 20.6 to 23.4 weight percent of neodymium, 6.6 to 7.5 weight percent of praseodymium, 0.95 to 1.20 weight percent of boron, 0.4 to 0.6 weight percent of cobalt, 0.11 to 0.15 weight percent of copper, 2.0 to 2.4 weight percent of lanthanum, 1.7 to 2.1 weight percent of cerium, 1 to 5 weight percent of graphene, a remainder being iron. The graphene-containing rare earth permanent magnet material exhibits excellent temperature resistance, good conductivity and magnet properties even without any heavy rare earth elements like terbium or dysprosium, which dramatically reduces the cost, promotes the efficient utilization of rare earth resources and improves product quality. The preparation method within this invention is simple to realize, easy to control, cost-effective and has high production efficiency and stable product performances.

To provide a rare earth permanent magnet having as a main phase a compound with a Nd.sub.5Fe.sub.17 crystalline structure having strong coercive force. A rare earth permanent magnet having as a main phase a compound with a Nd.sub.5Fe.sub.17 crystalline structure, wherein when the composition ratio of the rare earth permanent magnet is expressed as R.sub.aT.sub.(100-a-b)C.sub.b, where R is one or more rare earth elements requiring Sm, and T is one or more transition metal elements requiring Fe or Fe and Co, a and b satisfy 18<a<40 and 0.5≤b, and a phase where R and C are denser than the main phase is provided in the grain boundary phase of the rare earth permanent magnet.

A rare earth magnet includes a main phase and a particle boundary phase and in which an overall composition is represented by a formula, (R.sup.2.sub.(1-x)R.sup.1.sub.x).sub.yFe.sub.(100-y-w-z-v)Co.sub.wB.sub.zM.sup.1.sub.v.(R.sup.3.sub.(1-p)M.sup.2.sub.p).sub.q.(R.sup.4.sub.(1-s)M.sup.3.sub.s).sub.t, where R.sup.1 is a light rare earth element, R.sup.2 and R.sup.3 are a medium rare earth element, R.sup.4 is a heavy rare earth element, M.sup.1, M.sup.2, M.sup.3 are a predetermined metal element. The main phase includes a core portion, a first shell portion, and a second shell portion. The content proportion of medium rare earth element is higher in the first shell portion than in the core portion, the content proportion of medium rare earth element is lower in the second shell portion than in the first shell portion. The second shell portion contains heavy rare earth elements.

A rare earth magnet includes a main phase and a particle boundary phase and in which an overall composition is represented by a formula, (R.sup.2.sub.(1-x)R.sup.1.sub.x).sub.yFe.sub.(100-y-w-z-v)Co.sub.wB.sub.zM.sup.1.sub.v.(R.sup.3.sub.(1-p)M.sup.2.sub.p).sub.q.(R.sup.4.sub.(1-s)M.sup.3.sub.s).sub.t, where R.sup.1 is a light rare earth element, R.sup.2 and R.sup.3 are a medium rare earth element, R.sup.4 is a heavy rare earth element, M.sup.1, M.sup.2, M.sup.3 are a predetermined metal element. The main phase includes a core portion, a first shell portion, and a second shell portion. The content proportion of medium rare earth element is higher in the first shell portion than in the core portion, the content proportion of medium rare earth element is lower in the second shell portion than in the first shell portion. The second shell portion contains heavy rare earth elements.

A metal atom cluster-embedded magnetic iron oxide nanoparticle (MION) is disclosed. The metal atom cluster is embedded in an iron oxide crystal matrix and has a content of 0.1% to 15%. A method for preparing the MION includes: dissolving a metal precursor of iron oxide, an organic acid, and an organic amine in an organic solvent to form a uniform reaction system; heating the reaction system to 150° C. to 350° C. in an inert gas atmosphere; adding a metal atom cluster precursor; and heating to perform a reflux reaction until the metal atom cluster precursor is completely decomposed. The MION shows improved magnetic properties due to the embedding of the metal atom cluster, and the iron oxide fully ensures the stability of properties of the nanoparticles. The nanoparticles are especially applicable to biomedical detection and therapy and other fields.

A metal atom cluster-embedded magnetic iron oxide nanoparticle (MION) is disclosed. The metal atom cluster is embedded in an iron oxide crystal matrix and has a content of 0.1% to 15%. A method for preparing the MION includes: dissolving a metal precursor of iron oxide, an organic acid, and an organic amine in an organic solvent to form a uniform reaction system; heating the reaction system to 150° C. to 350° C. in an inert gas atmosphere; adding a metal atom cluster precursor; and heating to perform a reflux reaction until the metal atom cluster precursor is completely decomposed. The MION shows improved magnetic properties due to the embedding of the metal atom cluster, and the iron oxide fully ensures the stability of properties of the nanoparticles. The nanoparticles are especially applicable to biomedical detection and therapy and other fields.

A method of making a rare earth magnet containing zero heavy rare earth elements includes a step of mixing the fine grain powder with the lubricant having a weight content of at least 0.03 wt. % and no greater than 0.2 wt. % for a period of between 1 and 2 hours. The step of pulverizing is further defined as jet milling the alloy powder with the lubricant using a carrier gas of argon or nitrogen. The method further includes a step of controlling oxygen content during the steps of melting, forming, disintegrating, mixing, pulverizing, molding, and sintering whereby the impurities including Carbon (C), Oxygen (O), and Nitrogen (N) satisfies 1.2C+0.6O+N≤2800 ppm. A rare earth magnet composition including C, O, and N whereby C, O, and N satisfies 1.2C+0.6O+N≤2800 ppm and has zero heavy rare earth elements.

A method of making a rare earth magnet containing zero heavy rare earth elements includes a step of mixing the fine grain powder with the lubricant having a weight content of at least 0.03 wt. % and no greater than 0.2 wt. % for a period of between 1 and 2 hours. The step of pulverizing is further defined as jet milling the alloy powder with the lubricant using a carrier gas of argon or nitrogen. The method further includes a step of controlling oxygen content during the steps of melting, forming, disintegrating, mixing, pulverizing, molding, and sintering whereby the impurities including Carbon (C), Oxygen (O), and Nitrogen (N) satisfies 1.2C+0.6O+N≤2800 ppm. A rare earth magnet composition including C, O, and N whereby C, O, and N satisfies 1.2C+0.6O+N≤2800 ppm and has zero heavy rare earth elements.

A caster assembly configured to process and store a material includes a reaction chamber, a storage assembly configured to store material processed in the reaction chamber, and a blower configured to process and store the material. The reaction chamber includes a vessel configured to hold the material in a melted state prior to processing and a powder generating assembly configured to receive the material from the melting vessel. The powder generating assembly includes a feeding chamber and a feeding device disposed at least partially within the feeding chamber. The feeding device includes at least one nozzle configured to inject inert fluid, where the fluid is a gas, liquid, or combination of the two into the feeding chamber and a material inlet through which the material is configured to flow into the feeding chamber to be exposed to the inert fluid, where the fluid is a gas, liquid, or combination of the two.