Microwave absorbing ferrite thin films for microwave heating of microstructured reactors

G. Kozlowski, P. Gao, E.V. Rebrov, J.C. Schouten, R. Kleismit, J. Cetnar, G. Subramanyam

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review


Nanocrystalline Ni0.5Zn0.5Fe2O4 thin films have been synthesized with various grain sizes by sol–gel method on polycrystalline silicon substrates. The morphology and microwave absorption properties of the films calcined in the 673–1073 K range were studied by using XRD, AFM, near–field evanescent microwave microscopy, coplanar waveguide and direct microwave heating measurements. All films were uniform without microcracks. The increase of the calcination temperature from 873 to 1073 K and time from 1 to 3h resulted in an increase of the grain size from 12 to 27 nm. The complex permittivity of the Ni-Zn ferrite films was measured in the frequency range of 2–15 GHz. The heating behavior was studied in a multimode microwave cavity at 2.4 GHz. The highest microwave heating rate in the temperature range of 315–355 K was observed in the film close to the critical grain size of 21 nm in diameter marked by the transition from single– to multi–domain structure of nanocrystals in Ni0.5Zn0.5Fe2O4 film and by a maximum in its coercivity.
Original languageEnglish
Title of host publicationMicroelectromechanical systems - materials and devices II : Symposium held December 1 - 2, 2008, Boston, Massachusetts, U.S.A. ; [Symposium GG, "Microelectromechanical Systems - Materials and Devices II" which was held ... at the 2008 MRS fall meeting in Boston, Massachusetts]
EditorsS. Vengallatore
Place of PublicationWarrendale
PublisherMaterials Research Society
ISBN (Print)9781605111117
Publication statusPublished - 2009

Publication series

NameMaterials Research Society Symposium Proceedings
ISSN (Print)0272-9172


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