Effect of 90\ifmmode^\circ\else\textdegree\fi{} Domain Walls and Thermal Expansion Mismatch on the Pyroelectric Properties of Epitaxial ${\mathrm{PbZr}}_{0.2}{\mathrm{Ti}}_{0.8}{\mathbf{O}}_{3}$ Thin Films

Effect of 90° Domain Walls and Thermal Expansion Mismatch on the Pyroelectric Properties of Epitaxial ${PbZr}_{0.2} {Ti}_{0.8} O_{3}$ Thin Films

J. Karthik, J. C. Agar, A. R. Damodaran, and L. W. Martin

Phys. Rev. Lett. 109, 257602 – Published 21 December 2012

Abstract

We have investigated the contribution of 90° domain walls and thermal expansion mismatch to pyroelectricity in ${PbZr}_{0.2} {Ti}_{0.8} O_{3}$ thin films. The first phenomenological models to include extrinsic and secondary contributions to pyroelectricity in polydomain films predict significant extrinsic contributions (arising from the temperature-dependent motion of domain walls) and large secondary contributions (arising from thermal expansion mismatch between the film and the substrate). Phase-sensitive pyroelectric current measurements are applied to model thin films for the first time and reveal a dramatic increase in the pyroelectric coefficient with increasing fraction of in-plane oriented domains and thermal expansion mismatch.

Received 7 May 2012

DOI:https://doi.org/10.1103/PhysRevLett.109.257602

Authors & Affiliations

J. Karthik, J. C. Agar, A. R. Damodaran, and L. W. Martin^*

Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA