Spatially resolved measurements of thermal transport in ferroelectric materials using scanning thermal microscopy

This necessitated development of a measurement protocol based on microscopic temperature sensing using Scanning Thermal Microscopy (SThM). The adopted method involved periodically Joule heating the sample of interest using a deposited thin metal bar transducer in conjunction with lock-in detection of the induced surface temperature oscillations by SThM.

Spatial variations in surface temperature recorded across the uniformly Joule-heated bar were then interpreted as resulting from microstructure-related variations in the thermal conductivity of the underlying sample.<br><br>Initially, a proof-of-principle imaging experiment was conducted, revealing thermal differences between alternating metal and ceramic strips in a commercial multilayer ceramic capacitor. The sample exhibited a thermal response resembling an effective medium, with additional localised contrast features corresponding to the spatial distribution of thermal conductivity.