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Title: Role of nanocrystallinity on the chemical ordering of CoxPt100-x nanocrystals synthesized by wet chemistry

Journal Article · · Physical Chemistry Chemical Physics. PCCP (Print)
DOI:https://doi.org/10.1039/c5cp01062d· OSTI ID:1235874
 [1];  [2];  [2];  [2];  [1];  [2]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States)
  2. Sorbonne Univ., Paris (France); CNRS, Paris (France)

CoxPt100–x nanoalloys have been synthesized by two different chemical processes either at high or at low temperature. Their physical properties and the order/disorder phase transition induced by annealing have been investigated depending on the route of synthesis. It is demonstrated that the chemical synthesis at high temperature allows stabilization of the fcc structure of the native nanoalloys while the soft chemical approach yields mainly poly or non crystalline structure. As a result the approach of the order/disorder phase transition is strongly modified as observed by high-resolution transmission electron microscopy (HR-TEM) studies performed during in situ annealing of the different nanoalloys. The control of the nanocrystallinity leads to significant decrease in the chemical ordering temperature as the ordered structure is observed at temperatures as low as 420 °C. Furthermore, this in turn preserves the individual nanocrystals and prevents their coalescence usually observed during the annealing necessary for the transition to an ordered phase.

Research Organization:
Brookhaven National Lab. (BNL), Upton, NY (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
SC00112704
OSTI ID:
1235874
Report Number(s):
BNL-111682-2015-JA; PPCPFQ; KC0403020
Journal Information:
Physical Chemistry Chemical Physics. PCCP (Print), Vol. 17, Issue 42; ISSN 1463-9076
Publisher:
Royal Society of ChemistryCopyright Statement
Country of Publication:
United States
Language:
English