Sound-velocity, attenuation and thermal-expansion measurements are reported on La1.85Sr0.15CuO4. From room temperature to just above Tc the sound velocity is found to soften significantly as the temperature is reduced. At Tc there is a drop of 150 ppm in accord with the thermodynamics of the superconducting transition, and below Tc, as the gap opens, there is a large increase in the sound velocity. The magnitudes of these effects are anomalously large.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics