Lattice strain in garnet single crystals caused by high-energy heavy ion irradiation

The effect of high-energy heavy ion bombardment on the lattice parameter of single crystal garnets is investigated. Lattice expansion normal to the surface corresponding to lateral compressive strain is observed via x-ray reflection topography and rocking curve analysis using a double-crystal diffractometer. Studied are (111) garnet wafers of differing composition and epitaxial ferrimagnetic iron garnet films on pure and MgZr-substituted (111) Gd₃Ga₅O₁₂ substrates. Using¹³²Xe and²⁰⁸Pb ions of 1.4MeV/nucleon specific energy, the lattice expansion increases approximately linearly with dose over several orders of magnitude. The specific lattice parameter change is approximately 10^-14 per ion per cm² for¹³²Xe ions. A triple epitaxial film is used to obtain strain depth profiles