Article thumbnail

Screw Dislocation Generation by Inclusions in Molecular Crystals

By Xiaodi Zhong (3208044), Alexander G. Shtukenberg (1672858), Theodore Hueckel (4707088), Bart Kahr (1438720) and Michael D. Ward (320885)

Abstract

Dislocations in crystals affect material properties and are essential for crystal growth near equilibrium, yet their genesis in the absence of external or internal stresses is unresolved. X-ray topography has revealed microscopic inclusions as dislocation sources, but the real-time creation of a dislocation by a particulate inclusion has not been reported. In situ atomic force microscopy (AFM) was used herein to visualize dislocation generation in an l-cystine crystal by a cube-like hematite particle embedded in, and slightly inclined with respect to, the l-cystine {0001} surface. The particle produced two pairs of heterochiral screw dislocations with opposing Burgers vectors. After overgrowth of the particle, dissolution in undersaturated solutions revealed the dislocations once again until the detachment of the particle exposed a flat basal plane devoid of dislocations, thereby corroborating the essential role of the particle. Hematite particles with their flat faces parallel or at high angle to the surface, as well as spherical poly­(styrene) particles, did not produce dislocations, suggesting that shape and orientation of the particle with respect to the step train advancing across the growing crystal surface are critical features for dislocation generation

Topics: Biochemistry, Microbiology, Biotechnology, Ecology, Virology, Space Science, Environmental Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, Physical Sciences not elsewhere classified, surface, crystal, dislocation generation, AFM, Molecular Crystals Dislocations, screw Dislocation Generation, cube-like hematite particle, heterochiral screw dislocations
Year: 2017
DOI identifier: 10.1021/acs.cgd.7b01292.s012
OAI identifier: oai:figshare.com:article/5722966
Provided by: FigShare
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • https://figshare.com/articles/... (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.