Growth of thin Mn films on W(110) studied by means of in-situ scanning tunnelling microscopy

The growth of Mn films on W(110) substrates has been investigated at room t emperature by means of in-situ scanning tunnelling microscopy (STM) and low -energy electron diffraction (LEED). Our results show that highly strained bcc F-Mn can be stabilized on W(110) by pseudomorphic growth up to a local thickness of three atomic layers. Sequences of STM images measured at the s ame location of the sample reveal that islands of the first and second mono layer grow anisotropically along the [001] direction of the substrate. The nucleation of roughly rectangular islands with a local coverage of five mon olayers starts when the total amount of deposited material exceeds 1.0 ML. Local coverages of four atomic layers do not occur. The onset of nucleation of fifth monolayer patches coincides with an increased Mn density, indicat ing the onset of strain relaxation. The growth of Mn/W(110) is compared to that of Fe on the same substrate. The evolution of the filling factor of di fferent layers is fitted by a simple model. (C) 1999 Elsevier Science B.V. All rights reserved.