Pyroelectric Properties and Local Piezoelectric Response of Lithium Niobate Thin Films

In this paper, comprehensive investigation of the pyroelectric properties and local piezoelectric response in ferroelectric film heterostructures is presented. The pyroelectric effect is determined by the dynamic method and the pyroelectric response is recorded for further analysis. It is shown that such studies are effective to analyze the self‐polarization phenomena, the stability of the polarized state, the determination of the ferroelectric phase fraction in the film structures, the characterization of grains with in‐plane and out‐of‐plane polarization and others. For example, thin film samples of ferroelectric LiNbO3 deposited by magnetron sputtering on silicon substrates are considered. The measurement results show that a part of the crystal grains (about 30%) in these films possessed the out‐of‐plane polarization directed from the free surface to the substrate and determined the peculiarities of the pyroelectric response and the vertical component of the local piezoelectric response.