Nanoscale disorder in pure and doped MgB2 thin films

• Published in: Superconductor science & technology 2010-09, Vol.23 (9), p.095008-095008
• Main Authors: Zhu, Y, Pogrebnyakov, A V, Wilke, R H, Chen, K, Xi, X X, Redwing, J M, Zhuang, C G, Feng, Q R, Gan, Z Z, Singh, R K, Shen, Y, Newman, N, Rowell, J M, Hunte, F, Jaroszynski, J, Larbalestier, D C, Baily, S A, Balakirev, F F, Voyles, P M
• Format: Article
• Language: English
• Subjects: Borides; Carbon; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; High-tc films; Magnesium compounds; Microstructure; Molecular beam epitaxy; Nanostructure; Physics; Properties of type I and type II superconductors; Superconducting films and low-dimensional structures; Superconductivity; Superconductors; Thin films; Vortex lattices ,flux pinning, flux creep
• ISSN: 0953-2048; 1361-6668
• DOI: 10.1088/0953-2048/23/9/095008

MgB2 thin films have superior superconducting properties compared to bulk MgB2 and demonstrate the potential for further improving the performances of MgB2 wires and tapes. Using transmission electron microscopy, we have characterized the microstructure of pure and C-doped MgB2 using various carbon sources grown by hybrid physical--chemical vapor deposition (HPCVD), and cold-grown--annealed film deposited by molecular beam epitaxy (MBE). The MgB2 HPCVD films increase in crystal quality in the order (MeCp)2Mg-sourced films, CH4-sourced films, B(CH3)3-sourced films, pure films, while the Hc2 values of these films follow the opposite order. The cold-grown--annealed MgB2 MBE film contains non-epitaxial