New Method Probes Nanoscale Electrostatic Effects

Electrostatic forces were used to observe charge transfer at the nanoscale between metal and dielectric materials. A new technique was developed to access information about charge transfer, which is a key component in processes such as storage in flash memories, electroforming in memristors, surface electrochemistry, and triboelectricity.

The implementation of contact mode Kelvin probe force microscopy (cKPFM) allows, for the first time, to study bias-induced changes of surface charges at high temporal and lateral resolutions, surpassing traditional non-contact KPFM. Observations of significant surface charge states at zero bias and strong hysteretic electromechanical responses due to dynamic charge trapping and de-trapping at a non-ferroelectric surface have significant implications for fields such as triboelectricity and piezoresponse force microscopy. In the past, electrostatic tip–sample interactions in contact mode were neglected for a variety of scanning probe microscopy–based techniques used to study electromechanical effects. The work presented here emphasizes how important it is to take electrostatic forces into consideration to avoid misinterpretation of experimental data.    

 

N. Balke, P. Maksymovych, S. Jesse, I. I. Kravchenko, Q. Li, and S. V. Kalinin, “Exploring Local Electrostatic Effects with Scanning Probe Microscopy: Implications for Piezoresponse Force Microscopy and Triboelectricity,” ACS Nano (2014).    DOI:10.1021/nn505176a

 

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