With our new Physical Property Measurement System (PPMS) by Quantum Design we have the ability to make the following measurements over a temperature range of 1.7K to 400K and magnetic fields up to 9 Tesla.

By making RUS measurements over a wide range of temperatures and fields, phase transitions in the solid samples (magnetic, superconducting, etc.) are studied. If a structural phase transition occurs, discontinuities are seen in the elastic constants and resonant frequencies at the critical temperature and field.

Since RUS returns all of the sample's elastic constants with no need to remount the sample, the temperature dependence of the elastic constants can easily be measured and compared to theoretical predictions.

Below: Data showing the elastic constant behavior of the unfilled skutterudite CoSb3 and the La-filled skutterudite La0.75Fe3CoSb12. The unusual low temperature behavior of the La-filled sample has been characterized by the presence of two low-energy localized modes.

Ref: Keppens, V. et al. Localized vibrational modes in metallic solids. Nature 395, 876-878 (29 October 1998).

Below: Data showing the temperature dependence of single crystal SrTiO3 near a structural phase transition. This transition occurs as the titanium-oxygen octahedron inside the cube of strontium atoms rotates about one of the (100) axes.

Ref: Migliori, A. et al. Resonant ultrasound spectroscopic techniques for measurement of the elastic moduli of solids. Physica B 183, 1-24 (1993).