Electromagnetic behavior of radar absorbing materials based on Ca hexaferrite modified with Co-Ti ions and doped with la [Comportamento eletromagnético de materiais absorvedores de micro-ondas baseados em hexaferrita de Ca modificada com íons Co Ti e dopada com La]

Abstract

Radar Absorbing Materials (RAM) are compounds that absorb incidental electromagnetic radiation in tuned frequencies and dissipate it as heat. Its preparation involves the adequate processing of polymeric matrices filled with compounds that act as radar absorbing centers in the microwave range. This work shows the electromagnetic evaluation of RAM based on CoTi and La doped Ca hexaferrite. Vibrating Sample Magnetization analyses show that ion substitution promoted low values for the parameters of saturation magnetization (123.65 Am2/kg) and coercive field (0.07 T) indicating ferrite softening. RAM samples obtained using different hexaferrite concentrations (40-80 per cent, w/w) show variations in complex permeability and permittivity parameters and also in the performance of incidental radiation attenuation. Microwave attenuation values between 40 and 98 per cent were obtained.