Abstract
Triple-axis spectrometry has been used to determine the magnetic excitations in YBa
2Cu
3O
7. Polarized measurements at 10 K show the scattering consists of a peak near 40 meV while 100 K data show a mostly flat continuum. At 10 K the 40-meV peak is found to be sharp in energy and anisotropic in momentum occupying a square portion of the Cu
O reciprocal lattice plane. The temperature dependence of the scattering is identical at the square side and corner. Polarized measurements show that the small background scattering observed at 100K disappears below the superconducting transition. Resonant absorption measurements made to examine the Cu phonons show no observable changes in the phonons at the superconducting transition.