Evidence for pseudomorphic growth of iron on copper

TLDR

Iron was deposited at room temperature in ultra‑high vacuum onto single‑crystal Cu(001) films, with thickness gradients produced by moving a shutter between source and substrate. Transmission electron micrographs and diffraction of the thin (<20 Å) iron layers revealed face‑centred cubic iron strained to match the copper, whereas thicker layers contained dislocations and small body‑centred cubic nuclei to accommodate the misfit.

Abstract

Abstract Iron was deposited at room temperature in ultra-high vacuum (5 × 10−8 Torr) onto single-crystal films of copper oriented with (001) parallel to their plane. A shutter was moved between source and substrate so that iron deposits in which there were thickness gradients were obtained. Transmission electron micrographs and diffraction patterns from the thin (less than about 20 Å) parts of the iron deposits showed that they were face-centred cubic and were strained to exactly match the copper substrates. The thicker parts of the deposits contained dislocations to accommodate part of the misfit between face-centred cubic iron and copper. They also contained small nuclei of body-centred cubic iron.