Radiation-induced defects in antiferroelectric thin films

Radiation effects on highly oriented antiferroelectric (AFE) PbZrO ₃ (PZ) films with a thickness of approximately 400 nm are investigated in view of their possible application as a temperature sensitive element in a new bolometer system for fusion devices like ITER. The films were prepared by pulsed laser deposition (PLD). The dielectric constant was measured in the frequency range from 1 to 250 kHz in a stepwise cooling mode (∼2 °C min^-1) from 400 °C to room temperature before and after irradiation to a fast neutron fluence of 2 × 10²² m ^-2 (E > 0.1 MeV). After irradiation, the films were annealed in several steps up to ∼400 °C to remove the radiation-induced defects. The results are discussed in terms of two kinds of radiation effects, i.e. structural defects (oxygen vacancies) and radiation-induced charges, trapped at defect structures. The measurements show significant differences to sol-gel PZ thin films, which is mainly explained by the high quality of the PLD films.