Oxygen vacancy defects in antiferroelectric PbZrO3 thin film heterostructures after neutron irradiation

Neutron irradiation effects on highly oriented antiferroelectric PbZrO3 (PZ) thin films are investigated in view of their possible application as a temperature sensitive element in an alternative bolometer system for fusion devices such as the International Thermonuclear Experimental Reactor (ITER). All films were prepared by a sol-gel technique or by pulsed laser deposition (PLD). The dielectric properties were investigated in a frequency range from 1 to 250kHz and at temperatures up to 400°C, prior to and after irradiation to neutron fluences of 0.5×1022, 1×1022, 2×1022, and 3×1022m−2 (E>0.1MeV). After irradiation, the films were annealed in several steps up to 400°C in order to remove the radiation-induced defects. The results are discussed in terms of a phenomenological model of radiation effects in PZ films, which takes into account structural defects, such as oxygen vacancies, and radiation-induced charges. We find that the films are most sensitive to neutron irradiation in the vicinity of the phase transistion temperature Tc. In addition, the structural order of the films as well as the interfaces play an important role. We find that the PZ heterostructures prepared by PLD are radiation harder than the sol-gel films. The dielectric properties of the PLD films are more or less unaffected by neutron irradiation up to a fluence of 3×1022m−2 (E>0.1MeV).