Vacancy-ordered (110) epitaxial films which had been deposited  in situ  onto (103) Cu3Ba2YO7 were studied. The ordered structure was interpreted as being a 2 x 2 x 2 superstructure with a long-range ordered arrangement of O vacancies in the film and a 2 x 1 surface superstructure with an ordered arrangement of surface O vacancies.

C.C.Diao, G.Oya: Journal of Applied Physics, 1995, 78[6], 4291-3