Constructing oxide interfaces and heterostructures by atomic layer-by-layer laser molecular beam epitaxy

Abstract

Applied physics: New technique for oxide interfaces Recent advances in synthesizing and engineering oxide interfaces and heterostructures have provided a powerful strategy for creating new artificial structures exhibiting phenomena not possible in other materials form. Now Professor Xiaoxing Xi at Temple University from the US collaborates with researchers from the US, Italy and China showing a success in constructing oxides with well controlled stoichiometry and atomic layer precision. The central method—atomic layer-by-layer laser molecular beam epitaxy (ALL-Laser MBE)—is built upon the combined strengths of molecular beam epitaxy and pulsed laser deposition. It allows not only the growth of thin films of a Ruddlesden-Popper phase La5Ni4O13, but LaAlO3/SrTiO3 interfaces. Remarkably, no oxygen vacancies are detected in the oxide interfaces because of the high oxygen pressures during the growth and the carrier density of the two-dimensional electron gas agrees with the electronic reconstruction mechanism.