High resolution spatial mapping of the electrocaloric effect in a multilayer ceramic capacitor using scanning thermal microscopy

Abstract

Scanning thermal microscopy (SThM) is emerging as a powerful atomic force microscope based platform for mapping dynamic temperature distributions on the nanoscale. To date, however, spatial imaging of temperature changes in electrocaloric (EC) materials using this technique has been very limited. We build on the prior works of Kar-Narayan et al (2013 Appl. Phys. Lett. 102 032903) and Shan et al (2020 Nano Energy 67 104203) to show that SThM can be used to spatially map EC temperature changes on microscopic length scales, here demonstrated in a commercially obtained multilayer ceramic capacitor. In our approach, the EC response is measured at discrete locations with point-to-point separation as small as 125 nm, allowing for reconstruction of spatial maps of heating and cooling, as well as their temporal evolution. This technique offers a means to investigate EC responses at sub-micron length scales, which cannot easily be accessed by the more commonly used infrared thermal imaging approaches.