Nonlinear Optical Diagnostics of Thin Polycrystalline Lead Zirconate Titanate Films

Nonlinear optical microscopy techniques have been used to study thin films of single-phase (perovskite) and two-phase (perovskite–pyrochlore) lead zirconate titanate (PZT) deposited on Pt/TiO 2 /SiO 2 /Si by means of radio-frequency magnetron sputtering at various target–substrate distances ( D = 30–70 mm). Results revealed inhomogeneous distribution of second-harmonic generation in spherulitic perovskite islands, including increased signal intensity at perovskite/pyrochlore interface, which may be related to a nonuniform distribution of mechanical stresses. Factors responsible for the observed strong variation in second-harmonic signal are discussed, including the mutual relationship between changes in the character of spherulitic structure and conditions of PZT film deposition depending on the target–substrate distance.