Experimental research on the residual magnetization of a rare-earth permanent magnet for a cryogenic undulator

摘要

The magnetic properties of commercial polycrystalline Nd2Fe14B (N50M,N45H,N40SH,N35EH) and Sm2Co17 (XG30/20,XG26/25,XG22/20) magnets at cryogenic temperatures were tested by using a comprehensive physical properties measurement system (PPMS).The results show that the spin tilt temperature Tst of Nd2Fe14B magnets is closely related to intrinsic coercivity Hci,N50M and N45H with smaller Hci show a residual magnetization jump at 235 K and 225 K,respectively.For Sm2Co17 magnets,in 50-300 K,with temperature decreasing,residual magnetization Mrc shows a nearly linear increase,while in 10-50 K,Mrc has little change.The research results provide a reference for cryogenic undulators and other high-precision cryogenic devices.