| Autor: |
Zhu, P. L., Xue, F., Liu, Z., Fan, Y. L., Jiang, Z. M., Yang, X. J. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; Aug2009, Vol. 106 Issue 4, p043907-043913, 6p, 2 Black and White Photographs, 6 Graphs |
| Abstrakt: |
The magnetic properties of SiO2/Fe/SiO2 nanocomposite films are studied by magnetic force microscopy and vibrating sample magnetometer. The films were fabricated by alternately depositing SiO2, Fe, and SiO2 on Si substrates with magnetron sputtering followed by thermal annealing. It is found that the annealing atmosphere significantly influences the sample structure, composition, and magnetic properties. The samples annealed in forming gas show much better magnetic properties than those annealed in vacuum and in N2. The saturation magnetization can reach 200 emu/g, fairly close to the value of bulk Fe, and the coercivity can reach 400 Oe, much higher than 10 Oe of the bulk Fe. X-ray photoelectron spectroscopic depth profile measurement was carried out to study the mechanism of the strong influence of annealing atmosphere. For the samples annealed in forming gas, Fe nanoparticles are mildly oxidized, forming thin shells of Fe2O3 surrounding them, which is beneficial for maintaining the ferromagnetic behavior and enhancing the coercivity of nanoparticles. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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