High critical current density under magnetic fields in as-grown MgB₂thin films deposited by molecular-beam epitaxy

Abstract

As-grown MgB2 thin films were prepared by a MBE method under the conditions of low temperature, low deposition rate and high vacuum for applications in electric devices. The MgB2 thin films deposited on MgO and Ti buffered ZnO substrates have considerably higher Jc under magnetic fields among MgB2 thin films reported before. The value of Jc for the MgB2 thin film deposited on Ti buffered ZnO has been 5.8 × 105 A cm−2 at 10 K, 5 T in the magnetic field applied parallel to the c axis. In the angular dependence of Jc, the peak of Jc attributable to c-axis-correlated pinning centres has been observed when the magnetic field was applied parallel to the c axis.

Microstructure of MgB 2 superconducting wire prepared by internal magnesium diffusion and in-situ powder-in-tube processes – Secondary phase intergrain nanolayers as an oxygen content indicator

“…Thus we can conclude that the MgO plates are oriented with (0 0 1) MgO planes parallel to (0 0 1) MgB2 MgB 2 planes. This mutual orientation of cubic MgO and hexagonal MgB 2 phases has already been observed and discussed [25][26][27][28][29][30][31]. 1 0 MgO [29].…”

“…The film was polycrystalline and it did not have any preferential in-plane orientation, only strong [0 0 1] MgB2 out-of-plane texture. Some other authors also published c-oriented MgB 2 thin film on (0 0 1) MgO substrate without any additional information about the in-plane orientation[26][27][28]. Tian et al showed clear epitaxial growth of (…”

Flux pinning properties of MgB2 thin films on Ti buffered substrate prepared by molecular beam epitaxy

“…High quality MgB 2 thin films are prepared by molecular beam epitaxy (MBE) [2] and electron beam evaporation (EBE) [3]. As-grown MgB 2 thin films deposited at low temperature by MBE and EBE have a high critical current density J c .…”

MgB2 SQUID for Magnetocardiography

“…We achieved a value of T C = 37 K by the MBE method, which is the same as that with HPCVD. Fujiyoshi et al report that the J C of the MgB 2 films on the Ti buffer layer is higher than that of MgB 2 on the substrates [16]. Therefore, the pinning force due to the grain boundaries at the MgB 2 film on the Ti buffer layer is stronger than that of other films.…”