Dependence of Epitaxial Ba(Fe1-xCox)(2)As-2 Thin Films Properties on SrTiO3 Template Thickness

作者：Lee S^*; Jiang J; Weiss J D; Bark C W; Tarantini C; Biegalski M D; Polyanskii A; Zhang Y; Nelson C T; Pan X Q; Hellstrom E E; Larbalestier D C; Eom C B

来源：IEEE Transactions on Applied Superconductivity, 2011, 21(3): 2882-2886.

DOI：10.1109/TASC.2011.2107722

• Iron pnictides
• pulsed laser deposition
• templates
• thin films

In our previous report, we demonstrated the growth of high-quality epitaxial Co-doped Ba(Fe1-xCox)(2)As-2 (Ba-122) thin films using single crystalline SrTiO3 (STO) templates on (La, Sr) (Al, Ta)O-3 (LSAT) substrates with pulsed laser deposition (PLD). Here, we report the dependence of the structural and superconducting properties of Ba-122 thin films on STO templates that were 2-150 unit cell (u.c.) thick. We obtained genuine epitaxial thin films with high crystalline quality and excellent superconducting properties for templates above a critical thickness, which was 50 u.c. for our growth condition. Although the quality of Ba-122 is excellent above the critical thickness, the best crystalline quality and superconducting properties were obtained on 100 u.c.-thick STO templates. The best-quality Ba-122 thin films show an on-set transition temperature (T-c,T- on-set) as high as 22.8 K, a transition width (Delta T-c) as narrow as 1.

• 出版日期2011-6