The influence of low temperature on gamma-ray irradiated permanent magnets.
The temperature effect on the magnetic property of gamma-ray irradiated Nd-Fe-B and Sr-Ferrite magnets has been investigated. When the permanent magnets are exposed to gamma-ray, it's magnetic and other related properties are declined with degree of dose. The decreased magnetic property by gamma-ray irradiation at low temperature is similar with the result of magnet at high temperature. The temperature effect on the gamma-ray irradiation at exposed moment is also regarded as one of the important parameters for the reduced magnetic properties. The gamma-irradiation at low temperature was carried out at 195 K, and the changed properties of two kinds of magnets before and after gamma-irradiation were comparatively studied. The increased demagnetization of the magnets were studied by Hall probe. And changed Curie temperature and micro-crystal structure of each permanent magnet by gamma-ray irradiation has been also studied. Moreover the strong and broad single line shape of ESR signal in the resonance magnetic field is attributed to unpaired electron of Fe2+ in the sample by the effect of gamma-ray irradiation.
Han
Young Chul
YC
Department of Chemistry, Pukyong National University, Busan 608-737, Korea.
Cha
Hyun Gil
HG
Kim
Chang Woo
CW
Ji
Eun Sun
ES
Kim
Young Hwan
YH
Kang
Dong In
DI
Kang
Young Soo
YS