Characterization of superconducting and magnetic materials with muon spin rotation and neutron scattering. Progress report, March 1996--August 1997 and final report, June 1988--August 1997

Abstract

This report represents the culmination of over nine years of research activity in the study of superconducting and magnetically ordered materials using the muon spin rotation ({mu}SR) and neutron scattering techniques. Because all the activities that took place up until March 1996 have been covered in previous annual reports, this final report includes only a brief overview of activities prior to that date, and concentrates on the period from March 1996 through August 1997. The primary activity undertaken in this project has been studies of high-temperature superconductors and their close chemical relatives with the {mu}SR technique. These experiments extend from early work done with a relatively primitive muon beam at the AGS of Brookhaven National Laboratory and large polycrystalline samples of the earliest known high-{Tc} materials to studies of very small high-purity single crystals of the best high-{Tc} materials currently available using the highest quality surface muon beams and specially-designed low-background spectrometers at the Tri-University Meson Facility (TRIUMF) in the past three years. During the period since the last annual report five {mu}SR experiments were done at TRIUMF with DOE support. A study of single-crystal high-temperature superconductors was done in July 1996. A study of the quasicrystal materials Gd{sub 8}Mg{sub 42}Zn{sub 50} and Tb{sub 8}Mg{sub 42}Zn{sub 50} was done by D.R. Noakes in collaboration with G.M. Kalvius of the Technical University of Munich and R. Waeppling of Uppsala University during the first week of December 1996. During the second week of December 1996 a study of the cryocrystals CH{sub 4} and CF{sub 4} was done by D.R. Noakes in collaboration with S. Storchak of Moscow State University and J.H. Brewer of the University of British Columbia. A study of high-{Tc} superconductors was done at TRIUMF during the third week of December 1996 by C.E. Stronach and D.R. Noakes.