J. Phys. IV France 07 (1997) C1-583-C1-584
Preparation and Magnetic Properties of Zn-Doped Fe3O4 Magnetic ColloidP.C. Kuo1, J.L. Pan1, C.H. Lin2 and D.R. Huang3
1 Institute of Materials Science, Taiwan University Taipei, Taiwan, China
2 Department of Materials Science, National Tsing Hua University, Hsinchu, Taiwan, China
3 Opto-Electronics & Systems Labo., ITRI, Hsinchu, Taiwan, China
Fe3O4 magnentic colloids were produced by co-precipitating a Fe2+, Fe3+, and Zn2+ containing solution with a NaOH solution at 70°C. Analyses results indicated that the Zn content of the Fe3O4 colloids was always less than the solution's Zn content. The difference was found to be the smallest when the colloid was precipitated at pH=l0. The σs values of the Fe3O4 colloid significantly improved by adding an appropriate amount of Zn ions and precipitaing it at an optimum pH value, pH=10. The optimum Zn ion content was 6.18 at%, which was corresponded to Zn0 · 1854Fe0 · 8145Fe2O4. At this composition the colloid's σe value was 94 eau/g, and increased by more than 34% of pure Fe3O4 colloid's σ value. By theoretical calculation the σe should increase 27.8%.
© EDP Sciences 1997