Study of radiation damage in an ion implanted rare-earth iron garnet crystal

Abstract

The potential of a combination of Rutherford backscattering and channeling with the 16O(α, α) 16O nuclear resonance at 3.045 MeV to study radiation damage in all sublattices of oxide crystals is demonstrated. As a model, (Y, Sm, Lu, Ca) 3,(Ge, Fe) 5O 12 epitaxial layers on 〈111〉 gadolinium-gallium garnets were subjected to 80 keV Ne + ion bombardment. It is shown that the lattice damage is different for different constituents. Heavy ions were found more off-site than oxygen. A 350°C anneal, showing optimum magnetic characteristics in bubble memory applications, leads to complete recrystallization of all sublattices down to a depth of 100 nm, but leaves a disordered layer between 100 and 300 nm depth. Supposedly, this layered structure causes enough strain to suppress hard bubbles, but it is still low enough not to influence other bubble properties.