Magnetic effects induced by self-ion irradiation of Fe films

Microscopic structure of a heavily irradiated material

“…There is however no qualitative difference between the two temperatures for a regime of the early linear stage of evolution associated with the creation of initial isolated Frenkel pairs and then the nucleation and growth of small dislocation loops. This underlies the important result that despite the increased mobility of the interstitial defects at 300 K, the basic processes seen here at 0 K remain the same, and also involve the creation of Frenkel pairs, the clustering of interstitials to nucleate dislocation loops, and the subsequent growth of loops leading to the formation of a dislocation Note that these high-dose simulations suggest that while the onset of the asymptotic microstructural state occurs at the dose close to φ ∼ 2.5 cDPA, the ultimate steady state develops at a somewhat higher dose φ 0 ∼ 5 cDPA, in agreement with experimental observations [33,38].…”

“…How do the above simulations compare with experimental observations? At the beginning of this study, we noted that the intrinsic relaxation timescales of evolution of microstructure may be macroscopic even if the temperature is relatively high, and can vary from hours [40,41] to weeks [42] and even months [38]. If the dose-rate is sufficiently high such that the corresponding irradiation timescale is shorter than the relaxation time of the evolving microstructure, athermal stress driven processes will dominate the evolution.…”

“…The magnitude of τ can be macroscopic. For example the microstructure of pure iron exposed to high-dose ion irradiation evolves over a period of approximately five months at room temperature [38]. The recovery of dislocation loops in aluminium at room temperature occurs on the timescale of 230 years [39].…”

RMATE: A device to test radiation-induced effects under controlled magnetic field and temperature

“…However, a few experimental and theoretical efforts have been done in order to elucidate the role played by magnetism in damage. It has been found that Fe + irradiation on ferromagnetic films induced changes in the magnetic state for various irradiation doses [11,12].…”

Kinetic Monte Carlo Algorithms for Nuclear Materials Applications

“…Resistivity recovery experiments, which consist of irradiating the sample at low temperatures and then annealing at increasing temperatures to observe the different stages of defect recombination, have proven to be particularly useful in identifying migration energies of point defects (Takaki et al 1983;Matsui et al 1988;Ullmaier 1991;Fu et al 2005). In magnetic materials such as Fe and FeCr alloys, other methods can also be used to understand changes in magnetic properties after irradiation, such as polarized neutron reflectivity (Papamilhail et al 2016a(Papamilhail et al , 2016b. As mentioned above, comparing fundamental calculations of defect properties and defect distributions to these experimental results can only be done with the use of a kinetic model.…”