Chapter 4Analysis Through X-Ray Diffractionof Polycrystalline Thin Films1
The purpose of this chapter is to present analytical methods through X-ray diffraction of polycrystalline thin films deposited on a substrate. These methods are numerous, and it is beyond the scope of this chapter to present an exhaustive description. We will limit ourselves here to give relevant information required for a first-level analysis of the structural characteristics of a thin film. There are four basic techniques for analyzing the structure of a material through X-ray diffraction: the phase analysis, the texture analysis, the stress analysis, and the microstructural analysis. These techniques will enable us to extract this information from diffractogram either through the intensity, from the position or from the width of the observed diffraction peaks, or by combining this information together.
The following information is indeed essential to understand the piezo/pyroelectrical properties of a material: the phase and the crystal structure to determine the symmetries of the crystalline structure (centro-symmetric or not), the crystallographic texture (or the existence of twins), which will depend on the “intensity” of the piezoelectric properties through their tensor characteristics, the residual stresses through the coupling between the elastic and dielectric phenomena of the system, the grains density or the dislocation density, structural defects that locally alter the ...