Growth mechanism of superconducting MgB2 films prepared by various methods

Abstract

The growth mechanisms of MgB2 films obtained by different methods on various substrates are compared via a detailed cross-sectional scanning electron microscopy (SEM) study. The analyzed films include (a) samples obtained by an ex-situ post-anneal at 900 degree of e-beam evaporated boron in the presence of an Mg vapor (exhibiting bulk-like Tc0 about 38.8 K), (b) samples obtained by the same ex-situ 900 degree anneal of pulsed laser deposition (PLD)-grown Mg+B precursors (exhibiting Tc0 ~ 25 K), and (c) films obtained by a low-temperature (600 - 630 degree) in-situ anneal of PLD-grown Mg+B precursors (with Tc0 about 24 K). A significant oxygen contamination was also present in films obtained from a PLD-grown precursors. On the other hand, it is clearly observed that the films obtained by the high-temperature reaction of e-beam evaporated B with Mg vapor are formed by the nucleation of independent MgB2 grains at the film surface, indicating that this approach may not be suitable to obtain smooth and (possibly) epitaxial films.

arXiv comment1 table, 4 figures, 17 references, 16 pages PDF file

References in corpus (5)

• Thin Film Magnesium Boride Superconductor with Very High Critical Current Density and Enhanced Irreversibility Field
• MgB2 superconducting thin films with a transition temperature of 39 Kelvin
• Superconducting MgB(2) films via precursor post-processing approach
• Superconducting magnesium diboride films with Tc \approx 24K grown by pulsed laser deposition with in-situ anneal
• Superconducting magnesium diboride films on Silicon with Tc0 about 24K grown via vacuum annealing from stoichiometric precursors

Cited by in corpus (12)

• In situ epitaxial MgB2 thin films for superconducting electronics
• In-situ growth of superconducting MgB2 thin films by molecular beam epitaxy
• Synthesis and Properties of c-axis Oriented Epitaxial MgB2 Thin Films
• Low Temperature Fabrication of MgB2
• Growth of c-oriented MgB2 thin films by Pulsed Laser Deposition: structural characterization and electronic anisotropy
• The structure of the superconducting gap in MgB2 from point-contact spectroscopy
• Superconducting properties of MgB2 thin films prepared on flexible plastic substrates
• Lessons from Oxypnictide Thin Films
• Nanogranular MgB2 thin films on SiC buffered Si substrates prepared by in-situ method
• Tunnel junctions on as-grown superconducting MgB2 thin films
• Effective Vortex Pinning in MgB2 thin films
• Superconducting gap structure and pinning in disordered MgB2 films