Studies on surface structures and growth of In ultrathin films on Mo(110) surface

The surface structures and growth mode of In ultrathin films on Mo(1 1 0) surface have been studied by reflection high energy electron diffraction (RHEED). Three kinds of two-dimensional superstructures alpha, beta and gamma were observed in nearly monolayer region of In thickness. The alpha structure exists stably in wide temperature range from RT to 600 degreesC. This surface structure is expressed as [1 0 1 4] in matrix notation and has an atomic arrangement of bcc(1 1 0) layer of 2root3/3 times as large as Mo(1 1 0) plane rotated by 54.7degrees resulting in inducing compression of In atom by 3.0% in [0 0 1](Mo) orientation. The beta structure expressed as [1 0 -2 7] in matrix notation appears from 600 to 700 degreesC and has a smaller surface density than that of a structure. The gamma structure expressed as [1 -1 1 2] in matrix notation appears as high temperature phase from 700 to 800 degreesC. SEM observation reveals that room temperature condensation takes place in accordance with Stranski-Krastanov growth mode. (C) 2004 Elsevier B.V. All rights reserved.