Optimal design of sintered Ce_9Nd_(21)Fe_(bal)B_1 magnets with a low-melting-point (Ce,Nd)-rich phase

A systemic investigation was done on the chemistry and crystal structure of boundary phases in sintered Ce9Nd21FebalB1 （wt%） magnets. Ce2Fe14B is believed to be more soluble in the rare-earth （RE）-rich liquid phase during the sintering process. Thus, the grain size and oxygen content were controlled via low-temperature sintering, resulting in high coercivity and maximum energy products. In addition, Ce formed massive agglomerations at the triple-point junctions, as confirmed by elemental mapping results. Transmission electron micros- copy （TEM） images indicated the presence of （Ce,Nd）Ox phases at grain boundaries. By controlling the composition and optimizing the preparation process, we successfully obtained Ce9Nd21FebalBx sintered magnets; the prepared magnets exhibited a residual induction, coerciv- ity, and energy product of 1.353 T, 759 kA/m, and 342 kJ/m3, respectively.

A modified radiofrequency ablation approach for treating distant lymph node metastasis in two patients with late-stage cancer

Patients with late-stage cancer commonly have distant lymph node metastasis;however,poor health often contraindicates surgical treatment.Although the quality of life and overall survival for these patients are low,there is neither a consensus nor a guide for treatment.Ablation technique and surrounding tissue damage are two possible reasons for limited study of radiofrequency ablation in patients with superficial distant lymph node metastasis.Here,we report two patients treated successfully with ultrasound-guided radiofrequency ablation for superficial distant lymph node metastasis.In these patients,deionized water was injected to the surrounding tissues of the lymph node to decrease heat injury.Results from these patients suggest that radiofrequency ablation may play an important role in the treatment of patients with distant lymph node metastasis.

Preparation of Sintered(Ce_(1-x)Nd_x)_(30)Fe_(bal)Cu_(0.1)B_1 Magnets by Blending Powder Method

Magnets with nominal compositions of （ Nd1-x Cex ） 30 Febal Cu0.1 B1 （x = 0, 0.15, 0.3 and 0.4, mass% ） have been fabricated by blending powder method. The remanence （B r）, intrinsic coercivity （He） and maximum en- ergy product （BH） of the RE2Fe14B type magnets deteriorated when Nd was replaced by Ce. The chemical composition and crystal structure of magnet were investigated systemically. Backscattered electron （BSE） and energy dispersive spectroscopy （EDS） results revealed that Ce-rich and Ce-lean matrix grains coexisted in the magnets. The magnetic coupling mechanism among the double hard magnetic phases was discussed. Low melting point RE-Cu phase was in favor of the formation of uniform continuous grain boundary. Transmission electron microscopy （TEM） investigation showed the presence of fcc （Nd,Ce）Ox phase in the grain boundary. When the Ce content was 15% of the total amounts of all the rare earth, the maximum energy product of the sintered magnet was 359.8 kJ/ms.

Development of Ce-based sintered magnets: review and prospect

Ce-based magnets have attracted extensive attention in both academia and industry due to their excellent property-price ratio and distinctive phase structures.Characteristically,Ce-based sintered magnets have widely tunable magnetic properties with changing Ce contents.Therefore,they can be used to meet many different application requirements from packaging market to driving motors,etc.The intrinsic magnetic properties,phase composition,and microstructures of the Ce-based sintered magnets with different Ce contents have been summarized.The service performances such as temperature stability,corrosion resistance,mechanical properties and thermal expansion of commercial Ce-based sintered magnets are introduced.The research and development trends of the Ce-based magnets in the future are pointed out.