The Hall coefficient RH is seen to rise rapidly with decreasing temperature in the hopping regime of the insulating Al70Pd22.5Re7.5 quasicrystal with a resistivity ratio r = ρ(4.2 K)ρ(300 K) equal to 24 and to exhibit the variable-range hopping behavior i.e. RH = R0T0HT1/4. The obtained value of T0H is much larger than the Mott's temperature T0 extracted from the conductivity in the hopping regime. This is contrary to the prediction of Gruenewald et al. [Solid State Commum. 64 (1987) 11] for disordered systems. No existing theories can account for this anomalous effect.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry