The influence of high-energy xenon irradiation on magnetization, Faraday rotation and FMR linewidth of single crystal YIG films

Single crystal Y
3
Fe
5
O
12
films have been irradiated with 6 MeV/u xenon ions. The temperature dependence of the saturation magnetization indicates that the resulting nuclear tracks have a well defined diameter of 18 nm. The temperature dependence of the Faraday rotation of the irradiated compared to as-grown films shows a different behaviour at low temperatures. This is attributed to a deviation of the sublattice moments in the boundary region of the tracks. The FMR linewidth of one of the irradiated films exhibits a maximum centered at 40 K which is characteristic for Fe
²⁺
centers. 10 hours annealing at 793 K reduces this maximum drastically. Annealing experiments on a Gd
1.9
Bi
1.1
Fe
4.6
Ga
0.4
O
12
film irradiated with 3 × 10
¹¹
cm
^-2
xenon ions of specific energy 1.4 MeV per nucleon yielded activation energies ranging from 0.9 eV up to 5 eV.