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Screw Dislocation Assisted Spontaneous Growth of HfB 2 Tubes and Rods
Author(s) -
Venugopal Saranya,
Jayaseelan Daniel Doni,
Paul Anish,
Vaidhyanathan Bala,
Binner Jon G. P.,
Brown Peter M.
Publication year - 2015
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.13615
Subject(s) - boron , materials science , dislocation , calcination , boric acid , rod , anisotropy , hafnium , dwell time , impurity , amorphous solid , crystallography , chemical engineering , composite material , metallurgy , chemistry , catalysis , organic chemistry , zirconium , optics , medicine , clinical psychology , alternative medicine , physics , pathology , engineering
The mechanism of anisotropic growth of HfB 2 rods has been discussed in this study. HfB 2 powder has been synthesized via a sol–gel‐based route using phenolic resin, hafnium chloride, and boric acid as the source of carbon, hafnium, and boron respectively, though a small number of comparative experiments involved amorphous boron as the boron source. The effects of calcination dwell time and Hf:C and Hf:B molar ratio on the purity and morphology of the final powder have been studied and the mechanism of anisotropic growth of HfB 2 has been investigated. It is hypothesized that imperfect oriented attachment of finer HfB 2 particles results in screw dislocations in the coarser particles. The screw dislocation facilitates dislocation‐driven growth of particles into anisotropic HfB 2 rods.