Ultra-fast dynamic deposition of EuBa2Cu3O7−δ-BaHfO3 nanocomposite films: Self-assembly structure modulation and flux pinning behaviors.

[Display omitted] • BaHfO 3 doped Eu 1 Ba 2 Cu 3 O 7-δ films was fabricated by an ultra-fast pulsed laser deposition. • The periodic change of growth conditions during the multi-turn dynamic deposition results a distinct lamellar structure in doped film. • A strong correlation between dopant content and BaHfO 3 self-assembly mechanism was established. • The predominant pinning mechanism transforms form random pinning to correlated pinning with the increase of dopant content. Structure modulation of rare-earth barium cuperates (REBCO) superconducting films plays an essential role in the flux pinning behaviors. In this paper, nano-composite EuBa 2 Cu 3 O 7−δ -BaHfO 3 (EuBCO/BHO) films were deposited by the ultra-fast pulsed laser deposition technique. All nano-composite films exhibited high-quality orientation under the growth rates up to 100 nm/s. TEM cross-sectional analysis reveals that the EuBCO/BHO films have a distinct lamellar structure, which is related to the periodic change of growth conditions during the multi-turn dynamic deposition. In addition, the morphology of BHO varies with dopant content, which suggests a strong correlation between dopant content and the BHO self-assembly mechanism. Consequently, the vortex behavior shifts from giant-flux creep to vortex-glass formation at the thermally activated flux flow region as the dopant content increases. The primary flux pinning behaviors change from random to correlated pinning with the increase of dopant content at 4.2 K. Due to the larger contribution of the correlated pinning machinimas, the 8% BHO-doped EuBCO film exhibits the highest J c value at 4.2 K, with moderate fields (below 8 T) among all the three films. At 4.2 K and 14 T, the 6% BHO doped EuBCO film has the highest F p value attributing to the predominate random pinning mechanism. [ABSTRACT FROM AUTHOR]