Dielectric nonlinearity in relaxor and ferroelectric thin films of chemically ordered PbSc_(0.5)Nb_(0.5)O_(3)

摘要

Dynamic nonlinear dielectric response of pulsed laser deposited epitaxial thin films of chemically ordered perovskite PbSc_(0.5)Nb_(0.5)O_(3) was experimentally studied and analyzed. Films deposited at 925 K exhibited relaxor-like behavior indicated by frequency dispersion of temperature of dielectric maxima T_(m), maximum in third-order dynamic nonlinear permittivity ε_(3)(T), and increase of scaled dynamic third-order nonlinear permittivity a_(sc) below T_(m). With decreasing deposition temperature, relaxor behavior was suppressed. Results are discussed in terms of film microstructure and random field strength.