Imaging of electromechanical phenomena in liquid environment

1. CNMS Staff Science Highlight Imaging of electromechanical phenomena in liquid environment • Scientific Achievement • Electromechanical phenomena characterization at the nanoscale in liquid environments has been achieved with a biased scanning probe microscopy tip. Contact resonance enhancement, and multi-frequency excitation and detection principles have been used to overcome the high electrical conductivity of the liquid mediumby effectively lowering the applied voltage and shifting to higher measurement frequencies. • Significance • Electromechanical phenomena are universal features of a broad set of materials including ferroelectrics, ionic systems such as batteries and supercapacitors, and biological systems, which often require a liquid environment for stability and functionality. A deeper understanding of characterization techniques in liquids will enable the observation of these phenomena in-situ. • Research Details • Ferroelectric thin film BiFeO3 was investigated using piezoresponse force microscopy (PFM) in liquid environments as model systems for electromechanical phenomena in general. • The use of advanced techniques for electromechanical characterization in liquid environments, focusing on the elucidation of flexural and torsional cantilever contact dynamics allow to image and manipulate ferroelectric domains in liquid. Imaging of electromechanical phenomena on the nanoscale in liquid using scanning probe microscopy. Tip-sample contact resonance spectra change dramatically going from ambient environment into liquid. The amplitudes of the contact peaks can be use to characterize bias-induced volume changes in the sample. N. Balke, S. Jesse, Y. Chu, S. V. Kalinin, ACS Nano 109, DOI: 10.1021/nn301489g (2012).