Recently, the collaboration such as group of institute of Shanghai university material Professor Du Juan and technology of material of Ning Bo of the Chinese Academy of Sciences and the Bao Ru side project institute's deputy researcher publishs a problem to be “Tripling Magnetic Energy Product In Magnetic Hard/soft Nanocomposite Permanent Magnets” and J in world-famous periodical Materials Today Physics. Mater. Sci. Technol. The problem is published to research a thesis for “High Magnetic Energy Product In Isotropic Nanocomposite Powders With High Percent Of Soft Phase Towards Ultrastrong Magnets” on. Quan Wei, Ma Longfei and fencing gold Kui are a paper collective the first author, professor Du Juan and Professor Zheng Jiang is joint newsletter writer.

Have freeboard magnetism to be able to accumulate the rice of soft good offer with content of small rare land the new generation magnetically hard material that complex magnetically hard material is the most possible implementation. Accept rice is compound film of rare earth permanent magnetism had obtained outclass the tall magnetism of single-phase magnet can be accumulated, achieved the breakthrough on function. However in accept rice the physical legal system of compound magnetic particle and lump magnet has the respect encountered bottleneck however, because accept rice structure exists on microcosmic organization adjusting control,this basically is a lot of difficulty, the measure that includes appearance of soft hard magnetism is controlled hard (normally > 20nm) , appropriate photograph composition and content of high soft magnetism appearance (normally<28% ) obtain hard, bring about photograph of soft hard magnetism to obtain ideal coupling condition hard. The SmCo/Fe(Co) accept rice of domestic explicit isotropy is compound the magnetism that rare earth obtains in magnetically hard material can be accumulated the biggest it is 19.2MGOe only, can obtain maximum under magnet of single-phase anisotropy of lab and commercial SmCo5 even. Professor Du Juan is engaged in material of magnetism of accept rice brilliant considering for years, research group passes data of brilliant of polyphase accept rice preparation of new technology of two paces preparation gave highest magnetism to be able to accumulate the isotropy SmCo/FeCo composite material that is more than 29MGOe, broke through rare earth of SmCo5 single-phase isotropy the maximum of 25MGOe of magnetically hard material. This is accept rice compound magnetically hard material studies rare earth domain milepost the significant progress of type.

Professor Du Juan studies the group is based on near future series to study achievement offerred much harder look compound the way that will raise remanence of rare earth permanent magnet, powdery body mixes the polyphase hard Na Mijing that developed to have remanence to enhance effect of a body controallable equipment new method. To magnetically hard material, composite material includes appearance of much harder look of much harder look hard - of good complex magnetically hard material and much harder look soft - rice of hard look accept is compound magnetically hard material. The new technology of two paces preparation that the group developed material of brilliant of rice of accept of much harder look: The base material of the Na Mijing that be not brilliant that the first pace uses raw material of two kinds of above to grind craft preparation to give height to disperse equably through optimized ball, the 2nd pace uses microtherm anneal or microtherm multistage is lukewarm press craft preparation Na Mijing compound pink body and the Na Mijing that send density high are compound a body material. What the material of accept rice brilliant that this craft preparation comes out can realize place to contain polyphase grain is even distributing; What contain appearance content successive and adjustable (0~50% ) ; Grain can implement the measure of accept rice brilliant of <20nm.

Graph rice of accept of 1 much harder look is compound the preparation process of magnetically hard material and small structure evolve into rare earth sketch map

Research group is based on polyphase Na Mijing material is controallable equipment technology, use Sm-Co alloy and Fe pink to be raw material, successful preparation gives magnetism to be able to accumulate the isotropy that is 23.6~29.1 MGOe body of pink of SmCo/FeCo of much harder look is mixed a body material, exceeded the maximum of 25MGOe of magnet of SmCo5 single-phase anisotropy, the magnetism of obtains isotropy SmCo/FeCo composite material can be accumulated is 9 times what magnetism of hard look of isotropy SmCo3 sheet can accumulate, it is 3 times what isotropy SmCo5 single-phase magnetism can accumulate. It is current that the biggest magnetism that this institute obtains can be accumulated isotropy accept rice is compound the magnetism of magnetically hard material can accumulate rare land record (see a picture 2) . The tall magnetism of composite material of Na Mijing of SmCo/FeCo of much harder look can accumulate obtain result from its special microcosmic organization structure: SmCo of much harder look basically includes 1:3With 1:5, still have a few 1:7Photograph and 2:17 photographs Sm-Co, fe element is contained in hard look composition; Soft photograph is the FeCo look that has high saturated magnetization strength (the microcosmic organization structure of composite material sees accept rice graph 3) . Among them the <10~15nm of average grain dimension of hard look, the <15~20nm of average grain dimension of soft photograph. When FeCo of soft magnetism photograph achieves 25~50% , magnetism can accumulate the level that can reach 25MGOe above.

Graph 2 isotropy are much harder the biggest magnetism of composite material can accumulate rice of photograph SmCo/FeCo accept (A) , with isotropy accept rice of the report the representative magnetism of complex magnetic body can accumulate contrast (B) .

Rice of accept of graph 3 SmCo/FeCo the microcosmic organization structure of composite material (A) , what contain photograph composition (B) , be contained basically mix forcedly the microcosmic organization sketch map of soft photograph (C) , composition line scans (D) .

Study the group is based on the representative SCI paper that above job publishs: J. Mater. Sci. Technol. 144 (2023) 161; Materials Today Physics, 26 (2022) 100750; J. Mater. Sci. Technol. 37 (2020)181; 35 (2019) 560. This job got the project on face of national science foundation (No. 52171184) save science foundation with Zhejiang major project (No. The support of LD19E010001) .

Relevant paper links:

Https://www.sciencedirect.com/science/article/pii/S1005030222008234

Https://www.sciencedirect.com/science/article/pii/S2542529322001481