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Updated: Jan 19, 2026
Synthesis of Metal Nanoparticles Supported on Carbon Nanotube with Doped Co and N Atoms and its Catalytic Applications in Hydrogen Production
Published on: December 6, 2021
Structure and Magnetism of Co2Ge Nanoparticles
Onur Tosun1, Frank M Abel2, Balamurugan Balasubramanian3,4
1Department of Physics and Astronomy, University of Delaware, Newark, DE 19711, USA. onurt@udel.edu.
Abstract:
The structural and magnetic properties of Co2Ge nanoparticles (NPs) prepared by the cluster-beam deposition (CBD) technique have been investigated. As-made particles with an average size of 5.5 nm exhibit a mixture of hexagonal and orthorhombic crystal structures. Thermomagnetic measurements showed that the as-made particles are superparamagnetic at room temperature with a blocking temperature (T) of 20 K. When the particles are annealed at 823 K for 12 h, their size is increased to 13 nm and they develop a new orthorhombic crystal structure, with a Curie temperature (T) of 815 K. This is drastically different from bulk, which are ferromagnetic at cryogenic temperatures only. X-ray diffraction (XRD) measurements suggest the formation of a new Co-rich orthorhombic phase (OP) with slightly increased c/a ratio in the annealed particles and this is believed to be the reason for the drastic change in their magnetic properties.
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