Thermomagnetic measurements are used to obtain the size distribution and anisotropy of magnetic nanoparticles. An analytical transformation method is described which utilizes temperature-dependent zero-field cooling (ZFC) magnetization data to provide a quantitative measurement of the average diameter and relative abundance of superparamagnetic nanoparticles. Applying this method to self-assembled MnAs nanoparticles in MnAs-GaAs composite films reveals a log-normal size distribution and reduced anisotropy for nanoparticles compared to bulk materials. This analytical technique holds promise for rapid assessment of the size distribution of an ensemble of superparamagnetic nanoparticles.
@article{arxiv.1005.3252,
title = {Determining Magnetic Nanoparticle Size Distributions from Thermomagnetic Measurements},
author = {R. S. DiPietro and H. G. Johnson and S. P. Bennett and T. J. Nummy and L. H. Lewis and D. Heiman},
journal= {arXiv preprint arXiv:1005.3252},
year = {2015}
}