Zusammenfassung
Inelastic neutron experiments confirm the previously reported anomalous
nature of the planar oxygen bond-stretching vibrations and furnish
further details. It is shown that the frequency of the linear breathing
mode is renormalized by 5 THz compared to insulating YBa2Cu3O6. Studies
of the Cu1-apical O bond-stretching vibrations demonstrate that frequencies,
line-widths and phonon intensities can well be understood within
the framework of a harmonic lattice dynamical model. This rules out
predictions of a double well potential and strong anharmonitity for
this type of vibration.
Nutzer