Nuclear Quadrupole Resonance in Amorphous Semiconductors *

Nuclear quadrupole resonance ( N Q R ) has provided a valuable tool for investigating the local structural order in semiconducting glasses. Measurements of N Q R lineshapes and spin-lattice relaxation times help elucidate the local structural order and the unusual vibrational properties, respectively, o f these glasses. In addition, N Q R lineshape measurements on samples that are made under condit ions that produce solids whose structures are far from equilibrium, such as fast-evaporated films or rapidly-drawn fibers, provide detailed information on the changes in the local structural order from that which occurs in the well-annealed amorphous semiconductors.