Structure and properties of various fast neutron irradiated magnets

Neutron irradiation allows the materials to transform to a state, in which the properties of material become different from an initial state. This paper presents the results of neutron irradiation of several magnetic materials including intermetallic compounds Nd2Fe14B and Er2Fe14B, multiferroics BiFe0.95Mn0.05O3 and Bi0.85La0.15FeO3, oxides LiMn2O4 and Li0.9FePO4. The fast neutrons (Eeff > 0.1 MeV) have been used in a fluence range from 1 × 1018 n/cm2 to 2 × 1020 n/cm2 at 340 K Er2Fe14B alloy becomes amorphous under irradiation, that results in the reduction of Curie temperature to about 200 K. Irradiation destroys charge ordering in LiMn2O4 leading to the transformation from an incommensurate antiferromagnetic to a commensurate ferrimagnetic structure. Neutron irradiation of BiFe0.95Mn0.05O3 oxide is accompanied by decreasing the amount of impurity phases. On the contrary, in Bi0.85La0.15FeO3 fast neutrons result in the appearance of impurity phases. Neutron irradiation distinctly affects the lattice parameters of Li0.9FePO4 compound even with the relatively low fluence.