Abstract
We demonstrate that the average size of the coated ferromagnetic Fe2O3 nanoparticles is controlled by the surfactant concentration in the coating solution. Magnetization as a function of this ratio first increases and then decreases exhibiting a peak. Surface area of the coated material shows inverse behavior, i.e. first decreases and then increases. Both curves have extreme at the same ratio of surfactant/substrate. We explain these features in terms of competition between surface and volume contribution to the total energy, where surface contribution is determined by the bonding energy between the surfactant SH-group and Fe2O3. We support our conclusions by employing transmission electron microscopy and elemental analysis.
| Original language | English |
|---|---|
| Pages (from-to) | 189-193 |
| Number of pages | 5 |
| Journal | Thin Solid Films |
| Volume | 340 |
| Issue number | 1 |
| DOIs | |
| State | Published - 26 Feb 1999 |
Bibliographical note
Funding Information:This research was partially supported by grant no. 94-00230 from the US-Israel Bi-national Science Foundation (BSF). T. Prozorov thanks the Ministry of Science and Technology for an Eshkol scholarship. R. Prozorov acknowledges support from the Clore Foundations. We thank Prof. Y. Yeshurun for making available for this study the facilities of the National Center for Magnetic Measurements in the Departments of Physics at Bar-Ilan University. The authors thank Dr. Shifra Hochberg for technical assistance.