Characterization of epitaxial Co-doped BaFe2As2 thin films

Abstract

We characterized epitaxial thin films of Co-doped BaFe2As2 deposited on MgO substrate by resistivity, Hall resistivity and magneto-optical imaging measurements. The Hall coefficient RH is negative at all temperatures and decreases with decreasing temperature. The films have high critical current density Jc greater than 1MA/cm2 at low temperatures as determined from transport measurements. While the differential magneto-optical images of the remanent state in the film confirm the high Jc values they also show the presence of extended defects. Furthermore, the angular dependence of Jc in these films exhibit a larger peak for H//c than for H//ab at low fields which probably arises from the presence of defects along the c-axis.