This page is under construction. If you have any questions about the techniques being developed, please contact Rachel!

Ultrasound also has uses in measurements of the fundamental properties of single crystals, such as identifying phase changes and measuring the elastic constants. For these measurements, ultrasonic echoes are measured and the velocity calculated from the time spacing between echoes.

The calculated velocity can then be used to calculate elastic constants. In the above sample, Gd₆₄Sc₃₆, for longitudinal waves generated along the crystal c-axis, C₃₃= ρv². Measuring C₃₃ over a wide range of temperatures and magnetic fields will show phase transitions. The figure below was plotted with C₃₃ shown by the colour scale.

Standard measurements use contact transducers, such as quartz, to generate and detect ultrasound. We are developing EMAT techniques to remove the need for couplant. In NDT, the required magnetic field is provided by a permanent magnet; however, here we have a superconducting magnet which is used to generate a magnetic field to change the sample properties.