Effect of neutron irradiation on some piezoelectric properties of PZT type ceramics

Soft and hard type piezoceramic sintered samples were subjected to neutron irradiation in fluxes up to 10$^{18}$ n/cm$^{2}$ and the changes of the basic properties brought about by irradiation were investigated. The results showed that intermediate irradiation levels of up to 10$^{15}$ n/cm$^{2}$ do not change significantly the properties, but higher levels changed them. Thus the electromechanical coupling factor, the dielectric permittivity and losses decreased while the mechanical quality factor increases with increasing neutron flux for both types of materials. Changes of the lattice constants a and c were also observed. The main defects produced by neutron irradiation are oxygen vacancies but they are not entirely responsible for the modification of the materials properties. Some other factors such as domain pinning and lattice deformation can contribute to the properties degradation