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Organometallic Synthesis of β‐CoAl Nanoparticles and β‐CoAl/Al Nanoparticles and Their Behaviour upon Air Exposure (Eur. J. Inorg. Chem. 11/2010)
Author(s) -
Cokoja Mirza,
Parala Harish,
Birkner Alexander,
Fischer Roland A.,
Margeat Olivier,
Ciuculescu Diana,
Amiens Catherine,
Chaudret Bruno,
Falqui Andrea,
Lecante Pierre
Publication year - 2010
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201090028
Subject(s) - nanoparticle , chemistry , bimetallic strip , passivation , coal , absorption (acoustics) , organometallic chemistry , nanotechnology , chemical engineering , catalysis , organic chemistry , layer (electronics) , materials science , engineering , composite material
The cover picture shows the reaction path followed to produce bimetallic CoAl nanoparticles (background image). Organometallic precursors such as AlCp* and [Co(η 3 ‐C 8 H 13 )(η 4 ‐C 8 H 12 ) offer the unique advantage of being easily reduced under dihygrogen, thus enabling access to alloyed β‐CoAl nanoparticles as evidenced by X‐ray absorption and diffusion techniques. As expected, these nanoparticles are highly reactive towards oxygen. The reaction starts with the selective oxidation of Al, with simultaneous segregation of Co. Known in the bulk, this phenomenon is studied for the first time on the nanometer scale. It is clearly evidenced by SQUID measurements: an increase in the ratio of segregated Co atoms is accompanied by an increase in the magnetization of the nanoparticles. To passivate the system, excess aluminum must be decomposed on top of the CoAl nanoparticles. This study evidences the relevance of organometallic chemistry for nanoalloy engineering. Details are discussed in the Short Communication by C. Amiens et al. on p. 1599.