Hall Effect and Resistivity Study of the Magnetic Transition, Carrier Content, and Fermi-Liquid Behavior in Ba(Fe1-xCox)2As2

The negative Hall constant R-H measured all over the phase diagram of Ba(Fe1-xCox)(2)As-2 allows us to show that electron carriers always dominate the transport properties. The evolution of R-H with x at low doping (x < 2%) indicates that important band structure changes happen for x < 2% prior to the emergence of superconductivity. For higher x, a change with T of the electron concentration is required to explain the low T variations of R-H, while the electron scattering rate displays the T-2 law expected for a Fermi liquid. The T = 0 residual scattering is affected by Co disorder in the magnetic phase, but is rather dominated by incipient disorder in the paramagnetic state.