EFFECT OF PARTICLE SIZE OF BaFe₁₂O₁₉ ON THE MICROWAVE ABSORPTION CHARACTERISTICS IN X-BAND

Abstract

Abstract-Present work deals with the microwave absorption characteristics of BaFe 12 O 19 of interest as radar absorbing material (RAM). There are very few reported works available where particle size has been critically analyzed for absorbing characteristics at microwave frequencies, therefore, in this paper microwave absorption properties of the BaFe 12 O 19 with different particle sizes were investigated. The results showed that the particle size had significant influence on the dielectric and absorption properties of the composites in the 8.2-12.4 GHz frequency range. BaFe 12 O 19 powder of different particle sizes were synthesized by varying the annealing time and it was observed that the real part of permittivity of the composite increases from 5.18 (average value) to 7.50 (average value) and imaginary part increases from an average value of 0.20 to an average value of 2.33, whereas the real part of permeability increases from 0.95 (average value) to 1.11 (average value) and imaginary part of permeability was measured in the range of 0.02 to 0.07. These changes in permittivity and permeability affects microwave absorption application. It is observed that the maximum bandwidth for average particle size of 240 nm is 3.02 GHz and with the increase in average particle size, microwave absorption properties increased.

Electric transport properties study of bulk BaFe12O19 by complex impedance spectroscopy

“…Though conventional spinel ferrites also possess equivalent magnetic properties but, the better microwave absorption property of hexagonal ferrites make them superior than the former. To reduce the radiation pollution caused by increasing number of electromagnetic sources and to suppress electromagnetic interference, barium hexaferrite (BaM) is emerged as an important class of microwave absorber [7][8][9][10][11]. BaM system retains hexagonal structure consists of a closepacked stacking of oxygen layers, with the iron (Fe) atoms distributed within three kinds of octahedral sites (12k, 2a and 4f2), one tetrahedral site (4f1), and one bi-pyramidal site (2b) which are coupled by super exchange interactions through the O 2 À ions [12].…”

Design and experimental verification of a thin broadband nanocomposite multilayer microwave absorber using genetic algorithm based approach

“…The permittivity and permeability values of developed materials have been measured through Poly Reflection/transmission method in the 8. 2-12.4 GHz frequency range at room temperature [11]. Si-Ti based ceramic powder S-T 3.…”

Selection of Core shell Material based Electromagnetic Wave Absorbers in 2 to18 GHz using TOPSIS and VIKOR Ranking Methods

“…Step 2: The comparative weights are calculated using the eigenvalues from the matrix as in Eqn. (2).…”