Temperature dependence of the sound velocity Vs in a La1.85Sr0.15CuO4 single crystal has been measured in the (c11 - c12)/2 mode and in the c33 mode under high magnetic fields up to 23T. In the field above 6T, Vs in the (c11 - c12)/2 mode anomalously decreases with decreasing temperature, followed by the increase below about 10K. In the c33 mode, similar behavior of Vs can be observed above 20T. Such a temperature dependence of Vs may suggest the existence of a strain sensitive narrow band near the Fermi level or a phase transition related to the flux line lattice.
ASJC Scopus subject areas