Events Calendar

AME Seminar

Speaker: Nina Balke , Oak Ridge National Laboratory

Talk Title: A Nanoscale View on Electromechanical Phenomena

Abstract: The ability to transform electrical energy into mechanical energy and vice versa is the foundation to many technologies in the area of information and energy, such as sensors, piezotronics, energy harvesting, piezoelectric, electrochemical, and polymer actuators, and artificial muscles. Despite the importance of electromechanical phenomena and numerous applications, fundamental interdisciplinary studies needed to understand, and control electromechanical phenomena on the nanoscale are lacking. Atomic force microscopy (AFM) is well suited to measure local volume changes in the picometer range and has a lateral resolution of 10s of nanometer which makes this an ideal technique to address electromechanical phenomena on the nanoscale. Despite the technical advances and the development of new SPM-based characterization techniques, the quantification of functional material parameters based on electromechanical phenomena is still elusive. The lack of quantitative and accurate measurement can also lead to the misinterpretation of relevant material physics. Only if quantitative material parameters can be extracted, can a correlation of nanoscale structure-function relationships be derived, and AFM can be integrated with techniques probing smaller or larger length and time scales as well as theoretical efforts for a full information integration across different disciplines. I will give an overview over which electromechanical phenomena can be probed quantitatively including electro-chemo-mechanical coupling to understand local electrochemical reactions and processes in electrochemical capacitors. Then I will talk in depth about AFM and ferroelectric materials and how the quantitative measurement of piezoelectric material properties led to the discovery of layered 2D van der Waals ferroelectrics with highly unusual material properties and functionalities based on the presence of four polar phases and high ion conductivity. These materials demonstrate, for the first time, how physical order parameter can be controlled by ionic degrees of freedom which will open new concepts for functional heterostructures and electronic devices.

Biography: Nina Balke received her Ph.D in Materials Sciences from the Technical University of Darmstadt, Germany, in 2006. After being a Feodor-Lynen fellow of the Alexander von Humboldt foundation at the University of California in Berkeley she became a research staff at the Center for Nanophase Materials Sciences at Oak Ridge National Laboratory in 2010. She is specialized in nanoscale characterization of electromechanical effects and electro-chemo-mechanical coupling using atomic force microscopy in oxides and vdW layered materials. Her scientific focus includes ferroelectrics, dielectrics, and energy storage materials as well as in-situ characterization of solid-liquid interfaces.



Host: AME Department

More Info: https://usc.zoom.us/j/92982374143

Webcast: https://usc.zoom.us/j/92982374143

Location: Online event

WebCast Link: https://usc.zoom.us/j/92982374143

Audiences: Everyone Is Invited

Contact: Tessa Yao

Event Link: https://usc.zoom.us/j/92982374143