Clara Pereira - Tailored design of CoxMn1-xFe2O4 nanoferrites: a new route for dual control of size and magnetic properties

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      “Tailored design of CoxMn1-xFe2O4nanoferrites: a new route for dual control of size and magnetic properties”, Carlos Fernandes, Clara Pereira,María Paz Fernández-García, André M. Pereira, Alexandra Guedes, Rodrigo Fernández-Pacheco, Alfonso Ibarra, M. Ricardo Ibarra, João P. Araújo, Cristina Freire, Journal of Materials Chemistry C 2014, 2, 58185828.   DOI: 10.1039/C4TC00429A

        ‡   Both authors contributed equally to this work.

       

      Abstract:

      This work reports the tailored design of novel mixed ferrite   nanoparticles,   CoxMn1−xFe2O4  (x = 0, 0.3, 0.7, and 1), through an optimized one-pot   aqueous coprecipitation process. The influence of the   substitution between Mn(II) and   Co(II) and of the alkaline agent, isopropanolamine   (MIPA) or NaOH, on the morphological, chemical and magnetic   properties of the nanomaterials was investigated. The joint   action between chemical substitution and type of alkaline agent   allowed a precise tuning of the particle size, magnetic   properties and inversion degree of the spinel structure. A wide   range of particle dimensions (from 3 to 30 nm) and saturation   magnetization (from 57 to 71 emu g−1)   was achieved. The increase of Co(II) content from   x = 0 to x = 1 led to a systematic decrease of   the particle size, regardless of the base type, which could be   modelled by an exponential decay function. For each Co : Mn composition, the use of MIPA instead of the   traditional NaOH promoted a three times reduction of the particle   size and simultaneously switched the magnetic state of the   CoxMn1−xFe2O4  nanomaterials from ferromagnetic to superparamagnetic. These   results constitute a step forward in the challenging quest for   high-performance magnetic nanoprobes by an eco-friendly synthesis   route.

      Address (URL): http://dx.doi.org/10.1039/C4TC00429A