Crossovers in the out-of-plane resistivity of superconducting single crystals
Département de Physique, Ecole Polytechnique Fédérale de Lausanne
CH-1015 Lausanne, Switzerland
Accepted: 28 September 2000
We report the in-plane () and out-of-plane () resistivities in the 4–800 K range on single crystals of high- cuprate with ( ). exhibits “usual” linear behavior and follows generally metallic-like, positive slope in the 150–400 K temperature range. There is a clear crossover to semiconductor-like behavior close to . However, for the first time in a chainless high- cuprate we observe a crossover above 500 K due to hopping conduction. Under high pressures the magnitude of strongly decreases, yet the slope does not change. This suggests that the out-of-plane charge transport is governed by the interplane tunneling rate.
PACS: 74.72.Fq – Tl-based cuprates / 72.15.Eb – Electrical and thermal conduction in crystalline metals and alloys / 74.62.Fj – Pressure effects
© EDP Sciences, 2000