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This content will become publicly available on November 27, 2018

Title: Dislocation nucleation facilitated by atomic segregation

Surface segregation—the enrichment of one element at the surface, relative to the bulk—is ubiquitous to multi-component materials. Using the example of a Cu–Au solid solution, we demonstrate that compositional variations induced by surface segregation are accompanied by misfit strain and the formation of dislocations in the subsurface region via a surface di˙usion and trapping process. The resulting chemically ordered surface regions acts as an e˙ective barrier that inhibits subsequent dislocation annihilation at free surfaces. Using dynamic, atomic-scale resolution electron microscopy observations and theory modelling, we show that the dislocations are highly active, and we delineate the specific atomic-scale mechanisms associated with their nucleation, glide, climb, and annihilation at elevated temperatures. As a result, these observations provide mechanistic detail of how dislocations nucleate and migrate at heterointerfaces in dissimilar-material systems.
Authors:
 [1] ;  [2] ; ORCiD logo [3] ;  [4] ;  [3] ; ORCiD logo [4] ;  [1] ;  [1] ;  [3] ; ORCiD logo [4] ;  [3] ;  [2] ;  [3] ; ORCiD logo [1]
  1. State Univ. of New York at Binghamton, Binghamton, NY (United States)
  2. Univ. of Michigan, Ann Arbor, MI (United States)
  3. Univ. of Pittsburgh, Pittsburgh, PA (United States)
  4. Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Report Number(s):
BNL-203569-2018-JAAM
Journal ID: ISSN 1476-1122
Grant/Contract Number:
SC0012704
Type:
Accepted Manuscript
Journal Name:
Nature Materials
Additional Journal Information:
Journal Volume: 17; Journal Issue: 1; Journal ID: ISSN 1476-1122
Publisher:
Nature Publishing Group
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; Atomistic models; Metals and alloys; Structural properties; Surfaces; interfaces and thin films; Transmission electron microscopy
OSTI Identifier:
1434777