Microstructure and Microwave Absorption Characteristics of BaTiO<sub>3</sub>-CoFe<sub>2</sub>O<sub>4</sub> Composites
Yuda Bakti Zainal, Dedi Dedi, Azwar Manaf
Abstract
Magnetic and dielectric phases like CoFe 2 O 4 and BaTiO 3 are both intrinsically capable of absorbing electromagnetic waves. The characteristics of the two phases in a composite structure to obtain the combined effect of the existence of phases as composite components have been investigated. Observation of the microstructure of composites with the composition (1-x)BaTiO 3 -(x)CoFe 2 O 4 has shown the compact structure of composite sample with an increased the mass density with increasing value of x. No changes in lattice constant of each phase in the composite structure. This ensures that no complete or partial substitution between the ions of each phase has occurred. However, the presence of a material phase in the composite structure influenced the crystallite growth behavior of each phase. The mean crystallite size of the two phases tends to increase, but grew with a different rate. The saturation magnetization value of the composite samples is composition dependent. The value of remanent magnetization and coercivity increases with increasing values of x. All composite samples based on the results of data evaluation data taken by a vector network analyzer (VNA) in X-band frequency, shows the ability to absorb electromagnetic waves in all X-band frequencies. Composite composition determined the peak frequency that gives the maximum reflection loss value. The largest maximum reflection loss value is-40 dB occurring at a frequency of 10.98 GHz from samples with a composition x = 0.5. In conclusion, the composite of CoFe 2 O 4 /BaTiO 3 system composite can be a promising candidate for electromagnetic wave dampers when the composite is properly designed.