Amorphization and De-vitrification in Immiscible Copper-Niobium Alloy Thin Films

While amorphous phases have been reported in immiscible alloy systems, there is still some controversy regarding the reason for the stabilization of these unusual amorphous phases. Direct evidence of nanoscale phase separation within the amorphous phase forming in immiscible Cu-Nb alloy thin films using 3D atom probe tomography has been presented. This evidence clearly indicates that the nanoscale phase separation is responsible for the stabilization of the amorphous phase in such immiscible systems since it substantially reduces the free energy of the undercooled liquid (or amorphous) phase, below that of the competing supersaturated crystalline phases. The devitrification of the immiscible Cu-Nb thin film of composition Cu-45% Nb has been studied in detail with the discussion on the mechanism of phase transformation. The initial phase separation in the amorphous condition seems to play a vital role in the crystallization of the thin film. Detailed analysis has been done using X-ray diffraction, transmission electron microscopy and 3D atom probe tomography.

Grantor dc:publisher

University of North Texas

Year dc:date

2007

Author dc:creator

• Puthucode Balakrishnan, Anantharamakrishnan

Contributors dc:contributor

• Kaufman, Michael
• Banerjee, Rajarshi
• Scharf, Thomas W.

• thin films
• atom probe
• phase separation
• clustering
• TEM
• Thin films.
• Copper.
• Niobium.
• Alloys.

Statement dc:rights

• Public
• Copyright
• Puthucode Balakrishnan, Anantharamakrishnan
• Copyright is held by the author, unless otherwise noted. All rights reserved.

Language dc:language

English

Identifier

oclc: 176634165
https://digital.library.unt.edu/ark:/67531/metadc3626/
ark: ark:/67531/metadc3626

OAI identifier oai:identifier

info:ark/67531/metadc3626