Nucleation and growth of a BCC Fe phase deposited on a single crystal (001) Cu film

Journal Article · Tue Jan 01 00:00:00 EST 1991 · Scripta Metallurgica; (United States)

DOI:https://doi.org/10.1016/0956-716X(91)90111-D· OSTI ID:5279635

Koike, J ^[1]

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1. Center for Materials Science, Los Alamos National Lab., Los Alamos, NM (US)

As a thin film overlayer grows on a substrate with a different structure, the overlayer initially adopts the substrate structure and subsequently transforms to an equilibrium bulk structure. such a growth characteristic has been extensively studied in Fe/Cu bicrystals. An Fe overlayer grown on a Cu substrate is known to have the fcc structure up to a thickness of 2 nm, whereas a thicker Fe overlayer consists of submicrometer grains of the bcc-Cu has been reported in a relatively thick Fe film and was found to consist of the Nishiyama (N), Kurdjumov-Sacks (KS), or Pitsch (P), depending on the orientation of the substrate surface. However, previous studies have not explained how the bcc structure nucleates or how the observed submicrometer polycrystalline grains form. The paper provides an understanding of these two points. Transmission electron microscopy (TEM) was used to study Fe/Cu bicrystals as the Fe thickness was varied systematically. Analysis of moire fringes, which are caused by superposition of different structures, enabled us to determine the orientation relationship between the very thin Fe layer and the Cu substrate. We show that a single variant of the P orientation relationship, which accompanies atomic rearrangement parallel to the interface, predominates at the nucleation stage of the bcc structure. Nucleation of other variants of P, N, and KS occurs with increasing Fe thickness and causes the formation of the submicrometer bcc grains.

• OSTI ID: 5279635
• Journal Information: Scripta Metallurgica; (United States), Vol. 25:1; ISSN 0036-9748
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
74 ATOMIC AND MOLECULAR PHYSICS
BCC LATTICES
NUCLEATION
COPPER
PHASE TRANSFORMATIONS
IRON
CRYSTALS
ELECTRONIC STRUCTURE
FCC LATTICES
GRAIN ORIENTATION
INTERFACES
SURFACE COATING
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CUBIC LATTICES
DEPOSITION
ELECTRON MICROSCOPY
ELEMENTS
FILMS
METALS
MICROSCOPY
MICROSTRUCTURE
ORIENTATION
TRANSITION ELEMENTS
360102* - Metals & Alloys- Structure & Phase Studies
640302 - Atomic
Molecular & Chemical Physics- Atomic & Molecular Properties & Theory