The influence of porosity on the electromechanical and pyroelectric properties of Ca-modified PbTiO3 thin films

The properties of Pb1-xCaxTiO3 (x = 0-30) thin films for electromechanical and pyroelectric applications can be further improved if porous, low-dielec tric constant layers are being used. The electric field dependent strain, p iezoelectric coefficient, pyroelectric coefficient and the pyroelectric fig ure of merit were evaluated as a function of the Ca-content and relative de nsity of the thin films. The heating-rate during the final anneal was obser ved to be the controlling parameter for the evolution of either dense or po rous microstructures. Both 2-methoxyethanol and 1,3-propanediol based solut ion precursors were used for spin-coating platinized Si3N4/SiO2/Si wafers. Microstructure-property relationships and electrical properties concerning the domain mobility were examined.