Abstract
Measurements of the electrical conductivity σ(T) and magnetoconductivity Δσ(H) of icosahedral and quasicrystals at low temperatures and in high magnetic fields H are reported. Below 0.2nK, σ of varies as σ(T)=+ with =30 and a<0. The conductivity decreases with increasing magnetic field. For σ(T) decreases with decreasing T and saturates at the level =1.7n below 0.1nK. In magnetic fields up to 40 kOe, Δσ(H) is negative below 1 K and σ(T,H) remains temperature-independent at the lowest temperatures. The optical conductivity σ(ω) is obtained from reflectivity data in the frequency range between 15 and . The main contributions to σ(ω) are a broad absorption signal centered at about 0.1neV and a sizable peak with its maximum at 2.6neV.
- Received 11 July 1996
DOI:https://doi.org/10.1103/PhysRevB.55.5730
©1997 American Physical Society