Dilatometer for thermal expansion & magnetostriction
Based on our miniature interferometer, we demonstrate the thermal expansion of Cu, Ti and Terfenol-D, as well as magnetostriction data on Terfenol-D and Invar over a wide range of cryogenic temperatures as well as in high magnetic fields. The cell effect is minimized by a suitable choice of materials, and compensated for by using a second reference beam in addition to the sample beam. The difference between both signals allows for the calculation of the thermal or magnetic strain. The measured resolution in our first demonstration reaches 1 nm on mm-sized samples, while the sensor resolution of 1 pm could reduce this down to 1 ppb.
more info on our dilatometer concept