Damage accumulation and recovery in gold-ion-irradiated barium titanate

Abstract

Single-crystal barium titanate (BaTiO 3) wafers were irradiated 60° off the surface normal at 170 and 300 K using 1.0 MeV Au 2+ ions over a fluence range from 0.03 to 0.19 ions/nm 2 . Disorder on both the Ba and Ti sublattices has been studied in situ using Rutherford backscattering spectrometry along the 〈1 1 0〉 axial direction. At these irradiation temperatures, the temperature dependence of disordering is small. The dose for amorphization under these conditions is on the order of 0.5 dpa, which is 50% of that required to amorphize SrTiO 3 under similar conditions. At low damage levels, recovery of disorder is observed at room temperature, suggesting at least one lower temperature recovery stage. For more highly damaged states, two distinct recovery stages have been identified between 420 and 570 K and between 720 and 870 K. The recovery stage between 420 and 570 K is associated with the critical temperature for full amorphization (∼550 K) in BaTiO 3. The higher temperature recovery stage is most likely associated with epitaxial recrystallization.