PHONON ANOMALY OF LA1.85SR0.15CUO4 STUDIED BY NEUTRON-SCATTERING

Inelastic neutron-scattering studies were performed on a powder and an assembly of single crystals of La1.85Sr0.15CuO4, T-c similar to 36 K. Phonon density of states and the Q-dependence of the dynamic structur e factor as well, as the details of the phonon-scattering function, we re investigated as a function of temperature. We found that specific p honon modes at the Brillouin zone centre and the zone boundary showed anomalous behaviour at T-c. Thus we suggest a strong correlation betwe en the phonon states and the superconducting states.