2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/28755Neutron scattering has been used to study the spin fluctuations in the YBa$_2$Cu$_3$O$_{7-x}$ and Bi$_2$Sr$_2$CaCu$_2$O$_8$ materials. Evidence is found for both incommensurate fluctuations and a commensurate resonance excitation. Measurements on the lattice dynamics for YBa$_2$Cu$_3$O$_{6.6}$ show incommensurate structure that appears to stem from charge fluctuations that are associated with the spin fluctuations.9 pages,LaTeX, 4 figures, proceedings of the 2nd international conference on stripes and High-Tc superconductivitySuperconductivitytext