Surface structures of Fe on Mo(1 1 0) surface investigated by RHEED

The surface structures of iron deposited on a Mo(1 1 0) surface have been investigated by reflection high-energy electron diffraction (RHEED), and three kinds of surface structures were observed. Up to 1.0 ML of Fe deposition thickneeses, 1 1 structure appeared in all substrate temperature range from RT to 1200 8C. At thicknesses ranging from 0.5 to 1.0 ML, a structure which is the commensurate structure expressed by [3 1, 0 2] in matrix notation appeared at 300–550 8C. More than 1.0 ML, the b structure appeared at 400–800 8C. The b structure is also the commensurate structure expressed by [12 0, 0 12], exhibiting the same atomic arrangement as bcc(1 1 0) surface. In the thickness range beyond 1.0 ML, Fe film grew as the Frank–van der Merwe growth mode at room temperature to 400 8C and Stranski–Krastanov growth mode from 400 to 800 8C, in which the b structure was the first monolayer.