The present invention relates to an R-T-B based permanent magnet material, having a composition of R.sub.xT.sub.yTm.sub.qB.sub.z (at. %), wherein 13≤x≤15.5, 0.5≤q≤3, 0.85≤z≤1, y=100−x−q−z; wherein R is LR.sub.aHR.sub.1-a, LR is one selected from the group consisting of Pr, Nd, PrNd, or a combination thereof, HR is one selected from the group consisting of Dy and Tb, or a combination thereof, and 0.95≤a≤1; wherein T is one selected from the group consisting of Fe and Co, or a combination thereof; and Tm is a transition metal. The advantage of the method is that: plating a heavy rare earth film on alloy flakes using a magnetron sputtering device, and the coercivity of the magnet is significantly increased simply by having a “core-shell” structure without long time diffusion heat treatment.

The invention pertains to advances in real-time methods in nuclear magnetic resonance by offering a new dual-frequency dynamic nuclear polarization (DNP) method that uses a microwave beam to polarize the spins of electrons and concomitantly act as a NMR transmitter.

The disclosure discloses a NdFeB permanent magnet and a preparation method thereof. The magnet is composed of main phase I, a shell structure, a grain boundary phase adjacent to the shell structure, a main phase II, a Ga rich region and a Cu rich region. The magnet has high remanence, high coercivity, and high magnetic energy. In addition, this method can significantly reduce the production cost.

An R-T-B-based sintered magnet and a preparation method therefor. The R-T-B-based sintered magnet comprises: R, B, Ti, Ga, Al, Cu, and T. The contents thereof are as follows: R is 29.0-33%; the content of B is 0.86-0.93%; the content of Ti is 0.05-0.25%; the content of Ga is 0.3-0.5%, but not 0.5%; the content of Al is 0.6-1%, but not 0.6%; the content of Cu is 0.36-0.55%. The percentage is the mass percentage. Under the condition that no heavy rare earth is added or a small amount of heavy rare earth is added, by using a low B technology, not only the remanence performance of the R-T-B-based sintered magnet is improved, but also the coercivity and the squareness of the magnet are ensured.

A neodymium-iron-boron permanent magnet, a preparation method and use thereof are disclosed. The neodymium-iron-boron permanent magnet has a composition represented by formula I: [mHR(1−m) (Pr.sub.25Nd.sub.75)].sub.x(Fe.sub.100-a-b-c-dM.sub.aGa.sub.bIn.sub.cSn.sub.d).sub.100-x-yB.sub.y formula I; where a is 0.995-3.493, b is 0.114-0.375, c is 0.028-0.125, d is 0.022-0.100; x is 29.05-30.94, y is 0.866-1.000; m is 0.02-0.05; HR is Dy and/or Tb; M is at least one selected from the group consisting of Co, Cu, Ti, Al, Nb, Zr, Ni, W and Mo.

A method of producing a SmFeN-based rare earth magnet, the method including: dispersing a SmFeN-based anisotropic magnetic powder comprising Sm, Fe, and N using a resin-coated metal media or a resin-coated ceramic media to obtain a dispersed SmFeN-based anisotropic magnetic powder; mixing the dispersed SmFeN-based anisotropic magnetic powder with a modifier powder to obtain a powder mixture; compacting the powder mixture in a magnetic field to obtain a magnetic field compact; pressure-sintering the magnetic field compact to obtain a sintered compact; and heat treating the sintered compact.

A neodymium-iron-boron permanent magnet, a preparation method and use thereof are disclosed. The neodymium-iron-boron permanent magnet has a composition represented by formula I: [mHR(1-m) (Pr.sub.25Nd.sub.75)].sub.x(Fe.sub.100-a-b-c-dM.sub.aGa.sub.bIn.sub.cSn.sub.d).sub.100-x-yB.sub.y formula I; where a is 0.995-3.493, b is 0.114-0.375, c is 0.028-0.125, d is 0.022-0.100; x is 29.05-30.94, y is 0.866-1.000; m is 0.02-0.05; HR is Dy and/or Tb; M is at least one selected from the group consisting of Co, Cu, Ti, Al, Nb, Zr, Ni, W and Mo.

A rare earth sintered magnet has a C concentration of 800-1,400 ppm, an O concentration of up to 1,000 ppm, and a N concentration of up to 800 ppm, an average crystal grain size D50 of up to 4.5 μm, and a degree of orientation Or (%) which is defined by the formula: Or (Br/4πIs)*100, wherein D50 and Or meet the relationship: Or>0.7*D50+95. The sintered magnet shows both high values of Br and H.sub.cJ.

Improved manufacturing processes and resulting anisotropic permanent magnets, such as for example alnico permanent magnets, having highly controlled and aligned microstructure in the solid state are provided. A certain process embodiment involves applying a particular orientation and strength of magnetic field to loose, binder-coated magnet alloy powder particles in a compact-forming device as they are being formed into a compact in order to preferentially align the magnet alloy powder particles in the compact. The preferential alignment of the magnet alloy powder particle is locked in place in the compact by the binder after compact forming is complete. After removal from the device, the compact can be subjected to a subsequent sintering or other heat treating operation.

The present invention discloses a high-resistivity sintered samarium-cobalt magnet and a preparation method thereof. According to the present invention, considering the specialty of sintered samarium-cobalt magnetic powder, fluoride or oxide is firstly prepared into nano-powder using high-energy ball milling, and the samarium-cobalt magnetic powder is prepared separately by rolling ball milling or high-speed jet milling, and then a certain electric field is applied in a fluoride suspension to drive the fluoride nano-powder to evenly cover a surface of the samarium-cobalt magnetic powder. The present invention breaks through the technical bottleneck that fluoride/oxide can improve the resistivity of a samarium-cobalt magnet but result in deterioration of the magnetic properties.