A precision radio-frequency (RF) transverse modulation technique based on a resonant tunnel diode oscillator (TDO) has been used to study the dynamic susceptibility in novel ring-shaped single domain Fe nanoparticles synthesized using reverse-micelle chemistry. Hysteresis loops measured using a SQUID magnetometer indicate a large coercivity (Hc = 400Oe) below the blocking temperature (TB ~52K). The dynamic susceptibility shows remarkable consistency with the M-H data and exhibits peaks at characteristic anisotropy fields. Overall, these RF experiments are well suited to probe the magnetic anisotropy in nanophase materials.
@article{arxiv.cond-mat/9904267,
title = {Dynamic transverse susceptibility in Au-Fe-Au "nano-onions"},
author = {H. Srikanth and E. E. Carpenter and C. J. O'Connor},
journal= {arXiv preprint arXiv:cond-mat/9904267},
year = {2007}
}