It was found that CuPt-A type ordering occurred in Al-rich AlInAs which had been grown on (001)InP substrates by means of solid-source molecular-beam epitaxy. Only triple-period-A type ordering in the [111]A directions had previously been reported for this system when grown under similar condition. Whereas the triple-period-A type ordering was observed in Al0.5In0.5As which had been grown with a (2 x 3) surface reconstruction, the CuPt-A type ordering was observed in Al-rich material; where the surface exhibited (1 x 2) surface reconstruction during growth. This provided strong support for the suggestion that the (1 x 2) reconstruction gave rise to CuPt-A type ordering.

Observation of CuPt A-type atomic ordering in AlxIn1-xAs alloys T.Suzuki, T.Ichihashi, T.Nakayama: Applied Physics Letters, 1998, 73[18], 2588-90