Transition Temperature Microscopy – Probing Thermal Properties of Coatings and Multilayer Films at the Micro- and Nanoscale

By Louis T. Germlnario, Clifford K. Schoff, Kevin KJoller, Craig Prater, Khoren Sahagian

Transition temperature microscopy (TTM) is a novel local thermal analysis technique that maps spatial variations in thermal properties on length scales from millimeters to nanometers. Traditional bulk thermal analysis provides a sample ­averaged result and cannot generally sup­ply sufficient information about complex structures or heterogeneities within films or coatings. There currently exists a na­noscale thermal analysis (nano-TA) tech­nique in which a nanoscale thermal probe heats a localized region on the sample surface to measure its thermal properties, including thermal transition temperatures like crystalline melting points and glass transitions.

TTM enables these nano-TA measurements to be carried out rapidly at a succession of points, thus creating automated high-resolution spatial maps of the thermal properties of a sample. In this article we also demonstrate how TTM can be used to characterize chemical and structural heterogeneities and thereby generate vital information in applications ranging from coating defects, to in-situ property measurement of individual layers in multilayered films, to the detection of gradients and interfaces.