[Gao, R. S.
; Zhen, L.
; Shao, W. Z.
; Sun, X. Y.
; Yang, L.] Harbin Inst Technol, Sch Mat Sci & Engn, Harbin 150001, Peoples R China
; [Gao, R. S.] Tsinghua Univ, Dept Mat Sci & Engn, Beijing 100084, Peoples R China
; [Hao, X. P.
; Wang, B. Y.] Chinese Acad Sci, Inst High Energy Phys, Key Lab Nucl Anal Tech, Beijing 100049, Peoples R China
Article; Proceedings Paper
Irradiation damage of FeCrCo, AlNiCo, SmCo, and NdFeB permanent magnets was investigated by using gamma-ray irradiation. Results of magnetic property measurement show that FeCrCo and NdFeB have more demagnetization than AlNiCo and SmCo. X-ray diffraction analysis shows that gamma-ray irradiation leads to the increase of FeCrCo crystal mismatch and decrease of AlNiCo ordering degree. The investigations by positron annihilation spectroscopy technique show that the defects in AlNiCo and SmCo increase after gamma-ray irradiation. The defects induced by gamma-ray irradiation in NdFeB magnets are not the main source that leads to partial demagnetization. The irradiation resistances of these magnets are discussed in detail considering the thermal stability, coercivity mechanisms, and defect damage. (C) 2008 American Institute of Physics.