Size-dependent magnetic parameters of fcc FePt nanoparticles: Applications to magnetic hyperthermia

M. S. Seehra, V. Singh, P. Dutta, S. Neeleshwar, Y. Y. Chen, C. L. Chen, S. W. Chou, C. C. Chen

Research output: Contribution to journalArticle

50 Citations (Scopus)

Abstract

For nominal 3 and 9 nm FePt nanoparticles coated with oleylamine/oleic acid and having a face-centred-cubic (fcc) structure, temperature variations (5-300 K) of magnetization M, ac susceptibility χ′ and χ″ for the frequency range fm = 0.1-1000 Hz and electron magnetic resonance (EMR) spectra at 9.28 GHz are reported. X-ray diffraction of the samples shows fcc structure with a lattice constant a = 3.84 and TEM characterization yields log-normal distributions of the particle sizes with average D = 3.15(0.16) nm and D = 8.70(0.12) nm for the 3 nm and 9 nm samples, respectively. M versus T data for the zero-field-cooled and field-cooled modes yield a blocking temperature TB = 15 K (85 K) for the 3 nm (9 nm) samples whereas the hysteresis loops at 5 K yield a coercivity Hc = 0 Oe (1.4 kOe). Analysis of the data of TB at different fm determined from the peaks in χ″ in ac susceptibility and the temperature variation of the EMR spectra are used to determine the following parameters of the Vogel-Fulcher relaxation for the 3 nm (9 nm) samples respectively: the attempt frequency fo = 8 × 1010 Hz (2 × 10 12 Hz); inter-particle interaction temperature To = 3 K (33 K) and anisotropy Ka = 1.96 × 106 ergs cm -3 (4.3 × 105 ergs cm-3). The use of the above parameters for the calculations of the optimum size for magnetic hyperthermia is analysed and discussed.

Original languageEnglish
Article number145002
JournalJournal of Physics D: Applied Physics
Volume43
Issue number14
DOIs
Publication statusPublished - 2010 Mar 30

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Acoustics and Ultrasonics
  • Surfaces, Coatings and Films

Fingerprint Dive into the research topics of 'Size-dependent magnetic parameters of fcc FePt nanoparticles: Applications to magnetic hyperthermia'. Together they form a unique fingerprint.

  • Cite this