Empirical relationship between δ and ferromagnetic resonance frequency in hexagonal ferrite-based microwave absorbing paint

This paper reports the development of an empirical relationship between delta and f(r) for a Mn-Ti-substituted barium hexagonal ferrite-based paint. The previously available empirical relation [1] is not valid beyond delta = 1.1, after which anomalous results are being obtained. An attempt ha been made to overcome this limitation by preparing different samples of ferritc using delta = 1.6. 1.7, 1.8, 1.9, 2.7, and 3.1 and experimentally determining their respective complex permeability. A plot has been obtained between delta and f(r) (resonant frequency) and, using the curve fitting techniques, a best-fitted curve was found, From this at? empirical relation could easily be derived. This relation was found to be valid for a wide frequency range from 8 GHZ to IS GHz. Results show that a maximum absorption on the order of 8 dB can be obtained at the resonance frequency of the various samples, thus successfully validating the relation. (C) 2003 Wiley Periodical, Inc.