Abstract
We report a study of the normal-state Hall effect and magnetoresistance
of single crystals of Tl2Ba2CuO6-delta. Using samples with T-c<15 K, we
can suppress the superconductivity down to low temperatures with
magnetic fields of 16 T, and can thus study the normal state properties
over three decades of temperature, extending into the T-->0 limit where
it is possible to make a reliable estimate of k(F) similar to 0.7
Angstrom(-1) from the Hall effect in the elastic-scattering regime. The
temperature dependence of the Hall coefficient, R(H), below 30 K rules
out models in which R(H)(T) is taken as a measure of a real
temperature-dependent change in the carrier concentration. The two
scattering rates (probed by the resistivity and the cotangent of the
Hall angle) which characterize normal-state transport in the cuprates
also appear in this overdoped material for T greater than or equal to 30
K. However, as T-->0, we observe only a single scattering rate, whose
temperature dependence is dominated by low power terms, in contrast to
the T-2 dependence predicted for a Fermi liquid. The relationship
between these findings and anomalous behavior previously reported for
the upper critical field is discussed.
