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Single‐Phase Filamentary Cellular Breakdown Via Laser‐Induced Solute Segregation
Author(s) -
Akey Austin J.,
Recht Daniel,
Williams James S.,
Aziz Michael J.,
Buonassisi Tonio
Publication year - 2015
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201501450
Subject(s) - materials science , nanosecond , silicon , metastability , atom probe , chemical physics , quenching (fluorescence) , supersaturation , branching (polymer chemistry) , nanoscopic scale , impurity , phase (matter) , optoelectronics , molecular physics , nanotechnology , laser , analytical chemistry (journal) , transmission electron microscopy , optics , fluorescence , composite material , chemistry , physics , organic chemistry , chromatography , quantum mechanics , thermodynamics
Nanosecond melting and quenching of materials offers a pathway to novel structures with unusual properties. Impurity‐rich silicon processed using nanosecond‐pulsed‐laser‐melting is known to produce nanoscale features in a process referred to as “cellular breakdown” due to destabilization of the planar liquid/solid interface. Here, atom probe tomography combined with electron microscopy is applied to show that the morphology of cellular breakdown in these materials is significantly more complex than previously documented. Breakdown into a complex, branching filamentary structure topped by a few nm of a cell‐like layer is observed. Single‐phase diamond cubic silicon highly supersaturated with at least 10% atomic Co and no detectable silicides is reported within these filaments. In addition, the unprecedented spatio‐chemical accuracy of the atom probe allows to investigate nanosecond formation dynamics of this complex material. Previously reported properties of these materials can now be reconsidered in light of their true composition, and this class of inhomogeneous metastable alloys in silicon can be explored with confidence.