Voltage-current characteristics of epitaxial and misoriented Ba(Fe1-xCox)2As2 thin films

Ba(Fe1-xCox)2As2 thin films were produced by Pulsed Laser Deposition (PLD). Epitaxial thin films were obtained when the deposition temperature was 700 °C while at 875 °C misoriented films were obtained. The presence of grain boundaries reduces the transport critical current Jc in almost two order of magnitude with respect to the textured thin films. The Voltage-Current (V-I) curves of misoriented films, exhibit a mixture of a non-ohmic linear differential (NOLD) and power law behaviors, due to the viscous flow of the flux lines along the grain boundaries lines, corresponding to the Jc limited by grain boundaries and Jc limited by intragrain, respectively. The misoriented thin films also present a kinked V-I curves attributed to a vortex channeling along the boundaries.