There are significant benefits in using a temperature stage along with a conventional AFM. The challenge is to design a temperature stage that can be conveniently used over a wide temperature range. The stage that has been developed for use with the micro-thermal analysis is shown below left.The stage uses liquid nitrogen cooling. Images can be acquired at -60°C as illustrated, without the need for a dry air box that would make the necessary adjustment of the microscope very difficult.

These images of a printed foil (topography top and DC thermal beneath) shown above, were obtained with the sample held at -60°C. This sample has a coating of glue that is too soft for thermal imaging at room temperature. By taking it below its glass transition temperature, the sample can be successfully imaged. Furthermore, below the results of localised thermal analysis are shown.

Note that measurement starts at -90°C. It shows the softening of the glue layer at -50°C followed by the melting of the substrate at about 150°C. Below is an image of a polyurethane sample taken with pulsed force mode at -50°C compared with the same area at room temperature.

By studying how different materials behave as a function of temperature, these kinds of images can be used to identify phases, also temperature can be used to make phases more apparent (see the articles on the use of variable temperature pulsed force mode). This is illustrated by the following series of pull-off force images from pulsed force mode applied to polystyrene on glass at elevated temperatures.

Note the dramatic changes in properties as a function of temperature. Finally the use of the temperature stage with phase contrast imaging and force distance curves is shown below. The two different polymers show very different behaviour near their glass transition temperatures. These types of experiment can also be used to identify materials as well as study micro-mechanical thermal properties.