The study of MgB2/BN/MgB2 trilayer films

• We fabricate MgB2/BN/MgB2 trilayer films.
• We study the films by XPS, TEM, SEM, XRD and MPMS.
• Both bottom MgB2 film and the BN film are epitaxial and smooth.
• Bottom MgB2 film is not deteriorated after growing the BN film.

MgB2/BN/MgB2 trilayer films have been fabricated by using hybrid physical–chemical vapor deposition (HPCVD) method for the MgB2 layers and chemical vapor deposition (CVD) method for the BN layers in the same reactor. The films are studied by X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD) and magnetization measurements. These test outcomes indicate the trilayer films are grown without deteriorating the superconductivity of MgB2 films. Our results show that it is feasible to grow MgB2/BN/MgB2 trilayer films in the same reactor sequentially, which has the advantage of reducing contamination during the growth. This therefore opens the door for fabricating all-MgB2 Josephson junctions by using the BN film as the insulating layer.