Control of gas phase nanoparticle shape and its effect on MRI relaxivity

Sitki Aktaş, Stuart C. Thornton, Chris Binns, Leonardo Lari, Andrew Pratt, Roland Kröger, Mark A. Horsfield

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We have used a sputtering gas aggregation source to produce Fe@FeO nanoparticles with different shapes, by annealing them at different temperatures in the gas phase. Without annealing, the most common shape found for the nanoparticles is cubic but annealing the nanoparticles at 1129 °C transforms the cubes into cuboctahedra. Measurements of the MRI relaxivity show that the cubic nanoparticles have a higher performance by a factor of two, which is attributed to a higher saturation magnetization for this shape. This indicates that the shape-control enabled by gas-phase synthesis is important for obtaining optimal performance in applications.
Original languageEnglish
Article number035002
Number of pages7
JournalMaterials Research Express
Issue number3
Early online date17 Feb 2015
Publication statusPublished - 17 Feb 2015


  • Nanoparticle shape control
  • MRI relaxivity
  • Core-shell nanoparticles

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