The spin-lattice relaxation time T1 of Si29 nuclei is measured near the metal-insulator transition as a function of temperature and magnetic field. The observed relaxation rate in the metal is up to 103 times larger than that for nuclei interacting with free, degenerate electrons. The enhanced relaxation rate and its magnetic field dependence suggest the existence of intrinsic, quasistatic spins with an ω-1 spectrum. These spins may cause strong spin-flip scattering and may therefore be responsible for the anomalous critical exponent of the electrical conductivity.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)