The near-field scanning thermal microscope.

We report on the design, characterization, and performance of a near-field scanning thermal microscope capable to detect thermal heat currents mediated by evanescent thermal electromagnetic fields close to the surface of a sample. The instrument operates in ultrahigh vacuum and retains its scanning tunneling microscope functionality, so that its miniature, micropipette-based thermocouple sensor can be positioned with high accuracy. Heat currents on the order of 10(-7) W are registered in z spectroscopy at distances from the sample ranging from 1 to about 30 nm. In addition, the device provides detailed thermographic images of a sample's surface.