Artificial and Self-assembled Vortex-pinning Centers in Superconducting Ba(Fe1-xCox)2As2 Thin Films

Here we study the microstructural and transport properties of Co-Ba122 thin films in which secondary non-superconducting phases have been introduced during film growth in two different ways: first by using a Co-Ba122 target with a small amount of oxygen, second by alternating two different targets: a clean CoBa122 and an undoped Ba122 target.