Preparation And Properties Of Tetrapod-shaped ZnO Whiskers Coated With Iron

Tetrapod-shaped ZnO (T-ZnO whisker) whisker which has unique tetra needle configuration, has special antistatic, antibacterial character. As a kind of microwave absorbing material, it belongs to electrical loss agent. To enhance the absorption of T-ZnO whisker at low frequency, Fe particles were prepared to coat the surface in the thermolysis of iron pentacarbonyl through chemical vapor deposition, the preparation, property and absorption mechanism were studied further.In this paper, Fe particles were coated in the surface of T-ZnO whiskers by controlling the quantity of iron pentacarbonyl and using proper reaction temperature. The structure of Fe/T-ZnO whiskers were analyzed by the means of XRD, the surface configuration were observed by the means of SEM, and the electromagnetic parameters as well as stabilization character of Fe/T-ZnO whiskers were measured and investigated.It was showed that reaction temperature and the content of Fe had effect on the coat of Fe/T-ZnO whiskers, when the temperature was raised to 250 centigrade degree, the content of Fe was between 10mol%-20mol%, the coat of Fe/T-ZnO whisker were well-proportioned and compact, thus it had good electromagnetic property. the Fe particles coat belonged to nano degree and the Fe/T-ZnO whiskers had better electromagnetic property than T-ZnO whiskers,ε′of Fe/T-ZnO whiskers was between 13.8~19.2,ε″was between 2.3~3.9,μ′was between 0.8~1.6,μ″was between 0.03~0.36, The simulation of the reflectivity showed that the absorption peak of Fe/T-ZnO whiskers moved to low frequency, it did good to improve the absorption property at low frequency and thicken the absorption band of T-ZnO whiskers.Comparing to T-ZnO whiskers mixed with carbonyl iron, Fe particles were coated in the surface of Fe/T-ZnO whiskers, which had lower density and better electromagnetic property with the same Fe content.It had no obvious effect on configuration and electromagnetic property of T-ZnO whiskers when it were placed at air atmosphere and 200 centigrade degree, the configuration of T-ZnO whiskers were changed when it were placed at 600 centigrade degree for a long time, while its electromagnetic and absorption property became weaker due to oxidation of the coat.