Abstract
The fabrication of a Ni/Al2O3/Ni heteroepitaxial junction was achieved by the post-hydrogen reduction of a NiO/Al2O3/NiO trilayered epitaxial thin film grown by pulsed laser deposition. The top and bottom NiO layers were selectively reduced to Ni metal layers showing epitaxial relationships, while the Al2O3 interlayer remained. The crystallographic and interfacial characteristics were confirmed by X-ray diffraction analysis, reflection high-energy electron diffraction, and transmission electron microscopy. The fabricated Ni/Al2O3/Ni heteroepitaxial junction exhibited atomically sharp interfaces with no amorphous boundary layer.