In thiswork,TPNRfilledFe3O4 nanocomposites withdifferent
filler weightpercentwerepreparedasmicrowaveabsorbing
materials. Themostpossiblemechanismtoexplaintheconstancy
in thevaluesof er
0 is orientationalpolarization.Thedielectricloss
in thesamplesatlowfrequenciesisverymuchinfluencedby
direct currentconductivity,whereasthelossathigherfrequencies
is attributedtoalternatingcurrentconductivity.Theferrites
exhibited domainwallresonanceinthelow-frequencyregime
with increaseinmagneticloss.Themicrowaveabsorption
properties analyzedbyusingaspecularabsorbermethodreveal
the existenceoftwomatchingconditionsofminimumreflection
at lowandhighfrequenciesforthesamethicknessofthesamples.
The firstmatchingconditionatlowfrequencyisdueto 9mr
*9¼9er
*9,
and thesecondmatchingconditionisduetothegeometrical
cancellation oftheincidenceandreflectedwavesatthesurfaceof
the absorber.Theincrementoffillercontentinthenanocompo-
sites canshiftthemaximumattenuationtoalowerfrequency,
increase maximumabsorbingeffectandalsoenlargetheabsorb-
ing bandwidth.Theminimumreflectionlosswasfoundincreasing
and movingtowardsthelowerfrequencyregionwithincreasing
of samplethickness.Conclusively,themicrowaveabsorbing
properties ofnanocompositesweredeterminedbythethickness
and thecompositionoffiller.Thedipfrequency,microwave
absorbing propertiesandtheabsorbingbandwidthofthe
nanocomposites canbemanipulatedeasilybychangingthefiller
concentration andthicknessofthesample.