Structural and ferroelectric properties of 0.9PMN-0.1PT thin films

ABSTRACT

Epitaxial films are a useful tool to study the interplay between the microstructure and the electrocaloric properties in order to optimize the performance of these materials. Therefore, epitaxial 0.9Pb(Mg_1/3Nb_2/3)O₃-0.1PbTiO₃ (PMN-PT) films were grown by pulsed laser deposition on (001)-oriented single crystalline SrTiO₃ (STO) substrates using an epitaxial La_0.7Sr_0.3CoO₃ buffer as bottom electrode and additional Au top electrodes on the surface of the PMN-PT layer. The main goal of our study was to characterize the influence of the laser fluence on the structural properties. Our data show that pyrochlore-free PMN-PT films can be realized for low fluences. The relative permittivity and the polarization were determined as a function of temperature to verify the ferroelectric quality of our films.

KEYWORDS:

• PMN-PT films
• epitaxial growth
• perovskite phase
• pulsed laser deposition

Acknowledgments

The work is partially funded by the DFG under grant no. HU1726/3 in the framework of the priority program SPP 1599 “Ferroic cooling.” The authors thank U. Besold for technical support as well as J. Scheiter for preparation of the cross-sectional FIB cuts and the SEM images.