A novel resonant method based on a tunnel-diode oscillator (TDO) is used to study the dynamic transverse susceptibility in a Fe nanoparticle system. The magnetic system consists of an aggregate of nanometer-size core (Au)-shell (Fe) structure, synthesized by reverse micelle methods. Static and dynamic magnetization measurements carried out in order to characterize the system reveal a superparamagnetic behavior at high temperature. The field-dependent transverse susceptibility at radio-frequencies (RF), for different temperatures reveals distinct peak structure at characteristics fields (H_k, H_c) which changes with temperature. It is proposed that relaxation processes could explain the influence of the temperature on the field dependence of the transverse susceptibility on the MI.
@article{arxiv.cond-mat/9911242,
title = {Dynamic Radio-Frequency Transverse Susceptibility in Magnetic Nanoparticle Systems},
author = {L. Spinu and H. Srikanth and E. E. Carpenter and C. J. O'Connor},
journal= {arXiv preprint arXiv:cond-mat/9911242},
year = {2009}
}
Comments
3 pages, 2-column, 3 figures, To be published in J. Appl. Phys. 2000 (44th Annual MMM proceedings)