Mechanisms of Electrical Conductivity in Y(1-x)CaxBa2Cu3O6.1 System
arXiv:cond-mat/0410763 · doi:10.1016/j.physc.2005.04.023
Abstract
Systematic studies of transport properties in deoxygenated Y(1-x)CaxBa2Cu3O6.1 series allowed to propose a diagram of conductivity mechanisms for this system. At intermediate temperature a variable range hopping (VRH) in 2 dimensions prevails. At lower temperature VRH in the presence of a Coulomb gap for smaller x and VRH in 2 dimensions for larger x are found. In a vicinity of superconductivity we observe conductivity proportional to \sqrt{T}. Thermally activated conductivity dominates at higher temperature. This diagram may be universal for the whole family of undoped high Tc related cuprates.
5 pages