bi-modal studies of complex oxides growth with RHEED and surface x-ray diffraction*

An oxide MBE chamber was developed for simultaneous use of RHEED and surface x-ray diffraction at the same time. It is mounted and coupled to a 6-circle diffractometer. X-ray reflection intensity measurement at one point in reciprocal space is similar to RHEED intensity oscillation measurement. The relationship between two methods has been reported for homo-epitaxial complex oxide growth [1]. With large photon flux at the Advanced Photon Source, the x-ray intensity measurement could be extended to a real-time collection of data on a large swath of a line scan utilizing multi-angle fly scans [2]. Rapid acquisition in the volume around x-ray diffraction rods and RHEED measurements were obtained simultaneously during the growth. This bimodal study was made during La₂CuO₄ (001) film growth on SrLaAlO₄ (001) substrates with MBE techniques. Discussed will be the relation between two different observations and future impacts from utilizing this bimodal method.
[1] M. C. Sullivan, et al, App. Phys. Lett. 106, 031604 (2015)
[2] Hawoong Hong, et al, App. Phys. Lett. 110, 021601 (2017)