FACE-CENTERED-CUBIC (111) TO BODY-CENTERED-CUBIC (110) TRANSITION IN EPITAXIAL FE ON CU(111)

X-ray photoelectron forward scattering and CO-titration measurements show that Fe agglomerates on Cu(111). Deposition of 6 monolayers of Fe at 300 K covers only approximately 90% of the substrate. However, deposition of 3 monolayers of Fe at 80 K covers approximately 95% of the substrate. The changing film morphology is reflected in the epitaxial phase of the Fe film. Fe deposited on Cu (111) at a substrate temperature of 80 K grows body-centered-cubic (bcc), but Fe deposited at a substrate temperature of 300 K initially grows face-centered-cubic and relaxes to bcc with increasing thickness. The changing epitaxial crystalline phase is discussed in terms of the intrafilm interaction strength relative to the film-substrate bond strength.