PrFeB magnets, which possess excellent magnetic properties at low temperatures, have important application value as cryogenic permanent magnet undulators for synchrotron radiation sources and free electron lasers. In ...PrFeB magnets, which possess excellent magnetic properties at low temperatures, have important application value as cryogenic permanent magnet undulators for synchrotron radiation sources and free electron lasers. In this research study, several high-performance PrFeB magnets(P42H, P48SH, and P48UH) were prepared, and their performance was comprehensively examined, including evaluations of their magnetic properties,microstructures, uniformity, and stability. Next,their application prospects were analyzed and discussed. In China, the first cryogenic permanent magnet undulators(CPMUs) with P48SH magnets with 18 mm cycle lengths have been developed. When the temperature is 80 K and the gap is 6.0 mm,the magnetic field measurement results of the CPMU showed that the effective magnetic field peak was approximately 0.92 T, yielding an increase of 11.76% relative to operation at 300 K, with an RMS phase error of about 4.99°.展开更多
The magnetic field stability of the PrFeB magnets is one of the key points which affect its application in such devices as cryogenic permanent magnet undulators. In this study, the magnetic properties and micro struct...The magnetic field stability of the PrFeB magnets is one of the key points which affect its application in such devices as cryogenic permanent magnet undulators. In this study, the magnetic properties and micro structure of PrFeB magnets, which were developed by the grain boundary diffusion, were examined. The demagnetizing field distribution of the cryogenic permanent magnet undulator made using the PrFeB magnets was simulated by Radia, and the change mechanism of the irreversible demagnetization following treatments at high temperatures was experimentally studied, The results show that the intrinsic coercivity of the PrFeB magnets can be increased by diffusion of Tb. Meanwhile, the remanence of the magnets displays almost no loss, and the increasing range is closely related to the orientation thickness of the PrFeB magnet, Therefore, the PrFeB magnets developed using grain boundary diffusion are found to have extremely high comprehensive magnetic properties, The irreversible demagnetization of the PrFeB magnets developed by grain boundary diffusion for the CPMU is determined to be significantly improved following high-temperature treatments.展开更多
For spin reorientation （SRT）, the applications of sintering NdFeB permanent magnets are limited at low temperature. The sintering PrFeB permanent magnet （PM） presents no SRT and shows excellent magnetic properties...For spin reorientation （SRT）, the applications of sintering NdFeB permanent magnets are limited at low temperature. The sintering PrFeB permanent magnet （PM） presents no SRT and shows excellent magnetic properties at low temperature. The magnetic properties of bulk polycrystalline sintering Prl-xNdxFeB （x = 0 and 0.8 correspond to P42H and N50M respectively） are studied in this paper. The results show that magnetic properties and stability of N50M are better than those of 42H at room temperature. With the decrease of temperature, the parameters ofBr, Hcb, and Hci of P42H present a nearly linear increasing trend; Br and Hcb of N50M first increase and then decline, Hci presents an increasing trend. At 77 K, Br, Hci, and Jr of P42H are increased by 18.7%, 308%, and 17.1% respectively over than those at 300 K; at 120 K, Br, Hci, and Jr of N50M are increased by about 16.19%, 245%, and 12.6% respectively over than those at 300 K. The magnetic properties of P42H are better than those of N50M at low temperature. The sintering PrFeB is the preferred PM in various low-temperature devices.展开更多
基金supported by project of the State Key Lab of Advanced Metals and Materials(No.2016-Z03)
文摘PrFeB magnets, which possess excellent magnetic properties at low temperatures, have important application value as cryogenic permanent magnet undulators for synchrotron radiation sources and free electron lasers. In this research study, several high-performance PrFeB magnets(P42H, P48SH, and P48UH) were prepared, and their performance was comprehensively examined, including evaluations of their magnetic properties,microstructures, uniformity, and stability. Next,their application prospects were analyzed and discussed. In China, the first cryogenic permanent magnet undulators(CPMUs) with P48SH magnets with 18 mm cycle lengths have been developed. When the temperature is 80 K and the gap is 6.0 mm,the magnetic field measurement results of the CPMU showed that the effective magnetic field peak was approximately 0.92 T, yielding an increase of 11.76% relative to operation at 300 K, with an RMS phase error of about 4.99°.
基金Project supported by the Natural Science Foundation of Shanghai(15ZR1448000)the State Key Lab of Advanced Metals and Materials(2016-Z03)
文摘The magnetic field stability of the PrFeB magnets is one of the key points which affect its application in such devices as cryogenic permanent magnet undulators. In this study, the magnetic properties and micro structure of PrFeB magnets, which were developed by the grain boundary diffusion, were examined. The demagnetizing field distribution of the cryogenic permanent magnet undulator made using the PrFeB magnets was simulated by Radia, and the change mechanism of the irreversible demagnetization following treatments at high temperatures was experimentally studied, The results show that the intrinsic coercivity of the PrFeB magnets can be increased by diffusion of Tb. Meanwhile, the remanence of the magnets displays almost no loss, and the increasing range is closely related to the orientation thickness of the PrFeB magnet, Therefore, the PrFeB magnets developed using grain boundary diffusion are found to have extremely high comprehensive magnetic properties, The irreversible demagnetization of the PrFeB magnets developed by grain boundary diffusion for the CPMU is determined to be significantly improved following high-temperature treatments.
基金Project supported by the Natural Science Foundation of Shanghai,China(Grant No.11ZR1445500)the National Natural Science Foundation of China(Grant No.11175238)
文摘For spin reorientation （SRT）, the applications of sintering NdFeB permanent magnets are limited at low temperature. The sintering PrFeB permanent magnet （PM） presents no SRT and shows excellent magnetic properties at low temperature. The magnetic properties of bulk polycrystalline sintering Prl-xNdxFeB （x = 0 and 0.8 correspond to P42H and N50M respectively） are studied in this paper. The results show that magnetic properties and stability of N50M are better than those of 42H at room temperature. With the decrease of temperature, the parameters ofBr, Hcb, and Hci of P42H present a nearly linear increasing trend; Br and Hcb of N50M first increase and then decline, Hci presents an increasing trend. At 77 K, Br, Hci, and Jr of P42H are increased by 18.7%, 308%, and 17.1% respectively over than those at 300 K; at 120 K, Br, Hci, and Jr of N50M are increased by about 16.19%, 245%, and 12.6% respectively over than those at 300 K. The magnetic properties of P42H are better than those of N50M at low temperature. The sintering PrFeB is the preferred PM in various low-temperature devices.
