Zn-magnetite nanoparticles for hyperthermia treatmentes

P. MENDOZA ZÉLIS; B. PIANZOLA ; M.B. FERNÁNDEZ VAN RAAP; S. STEWART; J. C. APHESTEGUY; A. FOSSATI; S. E. JACOBO; F. H SÁNCHEZ.

Manizales

Workshop; IX Latin American Workshop on Magnetism, Magnetic Materials and Their Applications; 2010

above 43 ºC and selectively kill tumor cells. One important feature of MNP for hyperthermia therapy is their specific loss power (SLP), which determines the heating rate during treatments. In this work ZnxFe(3-x)O4 (0 ≤ x ≤ 0.5) MNP and aqueous ferrofluids were prepared. Mean sizes (> 40 nm) and compositions were envisaged to produce high SLP. To this end, Zn concentration was varied to optimize the saturation magnetization Ms. Materials were characterized with several techniques to determine their structural, microstructural and magnetical properties and correlate them with their SLP performance. ZnxFe(3-x)O4 nanoparticles were prepared by coprecipitation from FeSO4/ZnSO4 precursors in basic pH and studied by Mössbauer Spectroscopy, TEM, DRX, SAXS, XAFS, magnetic thermogravimetry, VSM and RF-SLP. The nanoparticles have cubic-type shape with mean sizes of about 50 to 100 nm, decreasing with Zn concentration. It was observed that Zn2+ replaces Fe3+ at tetrahedric sites of the spinel structure increasing the Fe3+/Fe2+ ratio at the octahedric sites, similarly to what was reported for the bulk material; however, the highest Ms occurs at x = 0.1 – 0.2 (Ms ∼ 105 emu/g) instead of at x = 0.4 (bulk). The measured SLP in x=0 sample was 145 W/g. [1] Q. A. Pankhurst, N.K.T. Thanh, S.K. Jones and J. Dobson, J. Phys. D: Appl. Phys. 42 (2009) 224001 (15pp) Corresponding author: Tel.: + 54-0221-4246062; e-mail address: pmendoza@fisica.unlp.edu.ar TOPIC: Biomagnetics and magnetism in medicine TYPE OF PRESENTATION: Poster