Original Article Local piezoresponse and ferroelectric domain of sol-gel Pb(Zr x ,Ti 1-x )O 3 film Panya Khaenamkaew 1 , Igor K. Bdikin 2 , Aanrei L. Kholkin 2 and Supasarote Muensit 1,3* 1 Department of Physics, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90112 Thailand. 2 Department of Ceramics and Glass Engineering, University of Aveiro, Portugal 3 NANOTECH Center of Excellence at Prince of Songkla University, Hat Yai, Songkhla, 90112 Thailand. Received 9 December 2006 ; Accepted 27 December 2007 Abstract In this work Pb(Zr x Ti 1-x )O 3 (PZT) films with different thicknesses and compositions were prepared by a sol-gel method. Surface morphology and nanoscale behavior of single domain were mainly investigated by the piezoresponse force microscopy. Island-like and sun-rays types of grain and ferroelectric domain structures were observed. Changes of local hysteresis loops and magnitudes of the piezoresponses of the PZT films with different thicknesses and at different domains were systematically investigated. Keywords: Pb(Zr x Ti 1-x )O 3 , atomic force microscopy, piezoresponse, ferroelectric. Songklanakarin J. Sci. Technol. 30 (1), 59-63, Jan. - Feb. 2008 1. Introduction Researchers and engineers have long been focusing on ferroelectric materials due to their ability to transform electromagnetic, thermal and mechanical energy into electri- cal charge, which has been used in a number of electronic applications such as non-volatile computer memories and microelectromechanical systems. However, the scale of interest for determining the ferroelectric properties, the grain and domain structures is now nanoscale while the science of ferroelectrics at this scale is still scarce. The development of atomic force microscopy (AFM) has allowed the routine evaluation of surface topography of these materials. In the last few years an additional technique, i.e., piezoelectric atomic force microscopy (P-AFM or PFM), has been developed for determining the ferroelectric properties of a material (Snitka et al., 2006: Dunn and Whatmore, 2002). This work aims to fabricate thin films of Pb(Zr x Ti 1-x )O 3 or PZT, the most common conventional ferroelectric and piezo- electric materials, using the sol-gel method. Subsequently, the PZT films are characterized by the use of a piezoelectric atomic force or piezoresponse force microscopy (P-AFM or PFM) to determine the ferroelectric domains and the local piezoelectric hysteresis (d 33 -E) loops. 2. Methodology and Equations The PFM technique, in which the converse piezo- electric effect was employed, was mainly used in this work. The system comprised PFM tip in contact with the dielectric surface. The tip served as the top electrode. A weak ac voltage was applied between the conducting tip and bottom electrode to induce a local piezoelectric vibration, which is detectable by the same tip. The amplitude of the vibration signal provides information on the magnitude of the piezo- electric coefficient, while the phase signal determines the polarization direction. Due to the absence of the top elec- trode and consequent high resolution, one can observe the ferroelectric domains and the surface topography at the same *Corresponding author. Email address: supasarote.m@psu.ac.th http://www.sjst.psu.ac.th