Neutron and Raman scattering studies of HgBa2CuO4+δ

The HgBa2CuO4+delta sample was characterized by Neutron diffraction and magnetic measurements. Both of the measurements indicate a high purity of the sample. Raman measurement was performed on a HgBa2CuO4+delta compound of T-c = 96 K. The apical oxygen vibration at 592 cm(-1) was found to show (a) an above T-c anomaly, and (b) frequency hardening and linewidth broadening below the superconducting phase transition. The latter is attributed to the coupling of the phonon to the electronic excitation and related to the opening of the superconducting gap below the phonon frequency.