Air- and water-resistant noble metal coated ferromagnetic cobalt nanorods.
Cobalt nanorods possess ideal magnetic properties for applications requiring magnetically hard nanoparticles. However, their exploitation is undermined by their sensitivity toward oxygen and water, which deteriorates their magnetic properties. The development of a continuous metal shell inert to oxidation could render them stable, opening perspectives not only for already identified applications but also for uses in which contact with air and/or aqueous media is inevitable. However, the direct growth of a conformal noble metal shell on magnetic metals is a challenge. Here, we show that prior treatment of Co nanorods with a tin coordination compound is the crucial step that enables the subsequent growth of a continuous noble metal shell on their surface, rendering them air- and water-resistant, while conserving the monocrystallity, metallicity and the magnetic properties of the Co core. Thus, the as-synthesized core-shell ferromagnetic nanorods combine high magnetization and strong uniaxial magnetic anisotropy, even after exposure to air and water, and hold promise for successful implementation in in vitro biodiagnostics requiring probes of high magnetization and anisotropic shape.
†Laboratoire de Physique et Chimie des Nano-objets (LPCNO), Université de Toulouse; INSA, UPS, CNRS, 135 avenue de Rangueil, 31077 Toulouse, France.
Sergio
S
Lentijo-Mozo
†Laboratoire de Physique et Chimie des Nano-objets (LPCNO), Université de Toulouse; INSA, UPS, CNRS, 135 avenue de Rangueil, 31077 Toulouse, France.
Reasmey P
RP
Tan
†Laboratoire de Physique et Chimie des Nano-objets (LPCNO), Université de Toulouse; INSA, UPS, CNRS, 135 avenue de Rangueil, 31077 Toulouse, France.|‡Centre d'Elaboration de Matériaux et d'Etudes Structurales (CEMES-CNRS), 29 rue Jeanne Marvig, B.P. 94347, 31055 Toulouse, France.
Cécile
C
Garcia-Marcelot
§Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
Thomas
T
Altantzis
†Laboratoire de Physique et Chimie des Nano-objets (LPCNO), Université de Toulouse; INSA, UPS, CNRS, 135 avenue de Rangueil, 31077 Toulouse, France.
Pier-Francesco
PF
Fazzini
†Laboratoire de Physique et Chimie des Nano-objets (LPCNO), Université de Toulouse; INSA, UPS, CNRS, 135 avenue de Rangueil, 31077 Toulouse, France.
Teresa
T
Hungria
†Laboratoire de Physique et Chimie des Nano-objets (LPCNO), Université de Toulouse; INSA, UPS, CNRS, 135 avenue de Rangueil, 31077 Toulouse, France.
Benoit
B
Cormary
⊥Chemical Science and Engineering Division, Argonne National Laboratory, 9700 S Cass Avenue, Argonne, Illinois 60439, United States.
James R
JR
Gallagher
⊥Chemical Science and Engineering Division, Argonne National Laboratory, 9700 S Cass Avenue, Argonne, Illinois 60439, United States.
Jeffrey T
JT
Miller
∥IPREM-ECP CNRS UMR 5254, Université de Pau, Hélioparc Pau Pyrénées, 2 av. Pierre Angot, 64053 Pau Cedex 9, France.
Herve
H
Martinez
#Molecular Diagnostics, AIT Austrian Institute of Technology, Vienna, Donau City Strasse 1, 1220 Vienna, Austria.
Stefan
S
Schrittwieser
#Molecular Diagnostics, AIT Austrian Institute of Technology, Vienna, Donau City Strasse 1, 1220 Vienna, Austria.
Joerg
J
Schotter
†Laboratoire de Physique et Chimie des Nano-objets (LPCNO), Université de Toulouse; INSA, UPS, CNRS, 135 avenue de Rangueil, 31077 Toulouse, France.
Marc
M
Respaud
§Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
Sara
S
Bals
§Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
Gustaaf
G
Van Tendeloo
‡Centre d'Elaboration de Matériaux et d'Etudes Structurales (CEMES-CNRS), 29 rue Jeanne Marvig, B.P. 94347, 31055 Toulouse, France.
Christophe
C
Gatel
†Laboratoire de Physique et Chimie des Nano-objets (LPCNO), Université de Toulouse; INSA, UPS, CNRS, 135 avenue de Rangueil, 31077 Toulouse, France.
Katerina
K
Soulantica
cobalt; core−shell; ferromagnetic; nanorods; water resistant