Interferometric dilatometer for thermal expansion coefficient determination in the 4-300 K range

The measurement of thermal and mechanical properties of materials at cryogenic temperatures gains more and more importance in the field of the application of novel high-tech materials to aerospace industry and in developing scientific instrumentation. We present a simple and inexpensive interferometric dilatometer for the measurement of the thermal expansion of materials in the 4-300 K range. The dilatometer consists of a Michelson tilt-compensated interferometer in which the path difference is given by the variation in length of a sample enclosed in a 4 K cryostat. The compensation for misalignment permits a fast and simple operation routine that configures the instrument as a valuable tool for materials engineering.