Fabrication of cobalt-doped SrFe2As2 superconducting thin films

Abstract We have fabricated Co-doped bilayered SrFe 2 As 2 thin films on Al 2 O 3 (0 0 0 1) and LaAlO 3 (0 0 1) substrates by using a pulsed laser deposition (PLD) technique with a 248-nm-wavelength KrF excimer laser. In order to fabricate Co-doped SrFe 2 As 2 thin films, we used homemade target with an As-rich phase. We tried to find optimum growth condition by changing various experimental conditions, such as substrate temperature and laser energy density. The superconducting transition temperatures were influenced by growth temperature, but hardly affected by laser energy density. The best sample showed the T c of ∼20 K with a narrow superconducting transition width of 2.2 K.