In-situ X-ray diffraction on functional thin films using a laboratory source during electrical biasing

Abstract A methodology that allows the quantification of structural changes in functional thin films during the application of external electrical field is reported. The originality of this method is the development of a set-up using a laboratory X-ray source since most of previous Operando studies have used synchrotron radiations. Several technical challenges have been addressed: the (i) optimization of the electrical contact and the sample geometry within the lab-source goniometers, (ii) evaluation of any X-ray dose effect on the Metal/Insulator/Metal structure to prevent eventual charge accumulation at the electrode interfaces and (iii) the quantification of the effect of the time-delay, needed for X-ray measurement, on domain switching. The validity of our method has been demonstrated on a prototypic sol-gel lead zirconate titanate (PZT) thin film where the polarization and structural changes have been simultaneously measured. The evolution of ferroelastic domains as a function of external electric field has been quantified and two different effects have been successfully separated: (a) the cell extension and (b) domain wall motion described as the switching between a and c tetragonal domains.