Latest research on barium ferrite and SiC ceramic absorbing materials

The basic principle is to absorb electromagnetic waves on the surface of materials, and convert the energy of electromagnetic waves into other forms of energy through hysteresis loss or dielectric loss inside the material, and make the electromagnetic waves disappear due to interference, thereby losing the electromagnetic energy of detecting radar waves, destroying the integrity of detecting radar echo signals, and reducing the probability of radar detecting targets.
High performance absorbing materialsMeet the following requirements: The material should meet impedance matching characteristics to reduce surface reflection of electromagnetic waves, and the incident electromagnetic waves should be attenuated by the absorbing agent as fully as possible. At present, common absorbing materials include ferrite, SiC ceramics, and Si3N ¬ 4 ceramics. Below, Advanced Institute Technology will briefly share with you the recent research on absorbing materials.

BaFe12O19/NiFe2O4 nanoparticles with superparamagnetism were synthesized by co precipitation method using barium ferrite. The generated precursor was heat-treated at 800 ° C, 1000 ° C, and 1200 ° C in a Ni atmosphere. The particle size obtained by this process ranges from 20-22 nanometers and is spherical. In addition, thisSpherical nanoparticlesHexagonal at high temperatures and investigated the electromagnetic absorption performance in the X-band.

Graphic and textual introduction

SEM image of BaFe12O19/NiFe2O4 nanoparticles.

(a) Particles synthesized;

(b) Processed at 800 ° C;

(c) 1000 ° C processing;

(d) 1200 ° C processing.

Under the "synthesis" conditions, spherical nanoparticles with a size of 30-35nm were observed. As the heat treatment temperature increases, most of the nanoparticles will gradually disappear, and a small number of nanoparticles will absorb smaller particles, causing volume expansion. At 1200 ° C, BaFe12O19/NiFe2O4 nanoparticles (with a size range of 85-95 nm) have hexagonal plates and conical shapes.

2. The effect of temperature on the hysteresis loop of BaFe12O19/NiFe2O4 nanocrystals:

3. The effect of temperature on the reflectivity of BaFe12O19/NiFe2O4 nanocrystals:

Conclusion: Uniform spherical nanoparticles (30-35nm) of BaFe12O19/NiFe2O4 with superparamagnetism were successfully synthesized using co precipitation method. After heat treatment at 1200 ° C, hexagonal shaped nanoparticles (85-95 nm) were obtained with a high saturation magnetization of 55.188 emu/gm and a maximum reflectivity of -27.17 dB at 11.79 GHz.

The low-frequency dielectric properties of SiC ceramics indicate that SiC is covered by a SiO2 surface layer, leading to two types of thermal activation relaxation. Low frequency (high temperature) relaxation is a Maxwell Wagner relaxation caused by surface layer effects. High frequency (low temperature) relaxation is believed to be caused by the diffusion of oxygen vacancies from the surface layer into the interior of the sample
If you need this product or would like to learn more about related issues or product information, please contact us. We will solve your problems and provide services: