Spontaneous formation of hollow nanoparticles at room temperature: our recent work published in Nanoscale

Editor — Thu, 28 Feb 2013 16:09:46 +0000

In a paper recently published in Nanoscale, our group continues the exploration of the Kirkendall effect a room temperature: this time we report on the oxidation of cobalt nanoparticles at the air/water interface. We find that this results in the formation of hollow cobalt oxide shells, followed by decomposition of the shells into much smaller nanoparticles.

The work, carried out together with collaborators at ICMAB led by Prof. Jordi Arbiol, indicates that the presence of water modifies the reactivity on the nanoparticle surface favoring the formation of the hollow structure. The paper also presents detailed characterization, including the magnetic properties of some of the products. Overall, the work contributes to the understanding and control of the chemistry of hollow nanoparticles – a topic of growing interest due to their potential applications.

Varón, M., Ojea-Jimenez, I., Arbiol, J., Balcells, L., Martínez, B., & Puntes, V. F. Spontaneous formation of hollow cobalt oxide nanoparticles by the Kirkendall effect at room temperature at the water–air interface. Nanoscale, 5(6), 2429–2436 (2013).

http://pubs.rsc.org/en/content/articlelanding/2013/nr/c2nr32657d

Magnetic behavior of nanoparticle assemblies: our work in a new Scientific Reports paper

Editor — Thu, 14 Feb 2013 13:22:32 +0000

Thanks to an international collaboration carried out by Dr. Miriam Varón during her doctoral work, our group has recently published the paper “Dipolar Magnetism in Ordered and Disordered Low-Dimensional Nanoparticle Assemblies” in Scientific Reports. The work was led by Prof. Dr. Cathrine Frandsen from the Technical University of Denmark.

The paper presents the results on the use of electron holography to study 1D and 2D self-assemblies of magnetic (Cobalt) nanoparticles. The work reveals the correlation between particle arrangement and magnetic order, leading to the conclusion that ferromagnetism exists in these structures even in the absence of underlying crystallinity. This contributes not only to elucidating mechanisms at the nanoscale, but also to the application of nanoparticle assemblies in magnetic devices such as memories and sensors.

Varón, M., Beleggia, M., Kasama, T., Harrison, R. J., Dunin-Borkowski, R. E., Puntes, V. F., Frandsen, C. (2013). Dipolar Magnetism in Ordered and Disordered Low-Dimensional Nanoparticle Assemblies. Sci. Rep., 3.

http://www.nature.com/srep/2013/130206/srep01234/full/srep01234.html

(open access)

cobalt – Inorganic Nanoparticles Group

Spontaneous formation of hollow nanoparticles at room temperature: our recent work published in Nanoscale

Magnetic behavior of nanoparticle assemblies: our work in a new Scientific Reports paper