The effect of neutron irradiation on Sm/sub 2/Co/sub 17/-based high temperature magnets and Nd-Fe-B magnets

Monte Carlo study of radiation-induced demagnetization using the two-dimensional Ising model

“…For instance, it is known that magnets of higher coercivity typically exhibit better radiation resistance to the degradation of their magnetism [24]. This is particularly true of SmCo magnets when compared with other types of permanent magnets [11]. This feature is observed in our simulations [specifically in Fig.…”

“…This consequently transfers the energy to the lattice structure, as a thermal spike. Radiation-induced demagnetization is thought to be mainly due to the occurrence of such thermal spikes [11,12]. This is supported by the observation that an irradiated sample magnet recovers most of its magnetization (and in some cases full re-magnetization) upon its exposure to external magnetic fields [11,13].…”

“…Radiation-induced demagnetization is thought to be mainly due to the occurrence of such thermal spikes [11,12]. This is supported by the observation that an irradiated sample magnet recovers most of its magnetization (and in some cases full re-magnetization) upon its exposure to external magnetic fields [11,13]. The areas affected by such thermal spikes may undergo domain reversal due to the demagnetizing field of the magnet overcoming the coercive field [12,14] and it is now understood that the decay of magnetization in the sample is mainly caused by a process in which the spin of a large number of atoms is reversed through radiation-induced nucleation of a reverse domain with subsequent growth throughout the original domain [13].…”

An analysis of radiation effects on NdFeB permanent magnets

“…Such studies have examined the effects of neutrons [6], protons [7], X-rays [8], Bremsstrahlung radiation [9], gamma rays [10][11][12], electrons [13,14], and ions [15] on the magnetic field of permanent magnets. It has been observed that the amount of demagnetization depends on the type of radiation particle and the material of the magnet.…”

“…For instance, it was determined that electrons can cause more demagnetization than a higher dose of gamma rays [16]. It was also clear that Sm-Co type magnets had a higher tolerance for radiation than NdFeB magnets [6]. However, the mechanism of radiation-induced loss of magnetism is not completely understood.…”