Sm_2Co_(17)型永磁合金的辐照效应研究  

Irradiation effect of Sm_2Co_(17) type permanent magnets

作　　者：李哲夫[1] 贾彦彦[1] 刘仁多[1] 徐玉海[1] 王光宏[1] 夏晓彬[1] 

机构地区：[1]中国科学院上海应用物理研究所,上海201204

出　　处：《物理学报》2017年第22期242-249,共8页Acta Physica Sinica

基　　金：上海市自然科学基金(批准号:15ZR1448500)资助的课题~~

摘　　要：Sm_2Co_(17)型永磁合金大量使用在上海同步辐射光源储存环的永磁型波荡器上,在受到长期辐照后会发生磁性能损失的现象,进而影响同步辐射光的品质.为了探索其潜在的微观机理,本文首先对Sm_2Co_(17)型永磁合金所处混合辐射场的粒子及相关物理量进行了计算分析,确定引发磁性能损失的主要粒子是中子.然后采用Ar离子模拟中子辐照损伤的方法对其进行辐照,采用透射电镜对其辐照前后的微观形貌及微观结构进行了研究探讨,采用振动样品磁强计对永磁合金辐照前后的饱和磁化强度进行了分析对比,并讨论了微观结构演化与宏观磁性能变化的联系.结果表明,Ar离子辐照后Sm_2Co_(17)型永磁合金饱和磁化强度的不可逆损失与微观结构变化有直接的关系,其2:17相从单晶结构转变为非晶结构是造成其磁性能损失可能的微观机制.Insertion devices are crucial parts of the third generation of synchrotron radiation facility and free electron laser devices. The use of insertion device can improve the brightness and coherence of synchrotron radiation light. Undulator,one kind of insertion device, is largely installed in the storage ring of Shanghai synchrotron radiation facility. The main part of undulator is the device of magnetic source which consists of periodically arranged permanent magnets with the same magnetic field strength. In order to keep the normal electronic trajectory, a stable magnetic intensity in undulator is required. The Sm_2Co_（17） type permanent magnets with high intrinsic coercive force and good radiation stability are largely installed in the facility. However, the losses for magnetic properties of Sm_2Co_（17） type permanent magnets can be induced by longperiod irradiation in undulator through beam loss or mis-steering. The reduction of magnetic field could affect the electron energy, direction and the movement trajectory and so on, which seriously affects the amount of synchrotron radiation light. Microstructure of Sm_2Co_（17） type permanent magnet affects the macro magnetic properties and there is not any available report on the microstructure investigation of Sm_2Co_（17） type permanent magnet after being irradiated. Therefore, in this work, the effect of irradiation on the microstructure evolution is investigated. The radiation fields of Sm_2Co_（17） type permanent magnets and the main particles（neutron） that result in losing magnetic properties are first analyzed and confirmed by Monte Carlo code FLUKA calculation. Then, Sm_2Co_（17） type permanent magnet samples are irradiated by Ar ions at different fiuences to simulate neutron irradiation damage. Meanwhile, the microstructure evolutions of irradiated samples are characterized by transmission electron microscopy. Moreover, high resolution transmission electron microscopic images are taken at the peak of radiation damage field to further

关 键 词：Sm2Co17型永磁合金 辐照效应 饱和磁化强度 微观结构 

分 类 号：TG132.2[一般工业技术—材料科学与工程]