Thermo-dielectric, humidito-dielectric, and humidity sensing properties of barium monoferrite and barium hexaferrite nanoparticles

Barium monoferrite and M-type hexaferrite with generic formulae BaFe2O4 and BaFe12O19 were synthesized using the sol-gel method by annealing at 1000 degrees C. To confirm the phase and compositions, XRD and FTIR an-alyses were employed, and the formation of orthorhombic crystal structure of BaFe2O4 and hexagonal crystal structure of BaFe12O19 were observed. The surface morphology of the samples was investigated through the use of the scanning electron micrograph (SEM) technique. Energy dispersive X-ray spectroscopy (EDS) confirmed the chemical compositions of the samples. At room temperature, the real part of the dielectric constant (epsilon MODIFIER LETTER PRIME), the imaginary part of the dielectric constant (epsilon MODIFIER LETTER PRIMEMODIFIER LETTER PRIME), the dielectric loss tangent (tan delta), and AC conductivity (sigma AC) were measured at the specific frequencies (1, 1.5, and 2 MHz), and they were increased with both temperature and relative humidity (RH). Barium ferrite humidity sensors were created. The resistance of the sensor goes down as the RH% goes up, and the BaFe12O19 humidity sensor is 1.82 times more sensitive than the BaFe2O4 sensor.

Automated summary

Barium monoferrite (BaFe2O4) and M-type hexaferrite (BaFe12O19) were synthesized using the sol-gel method and their properties were investigated. XRD and FTIR analyses confirmed their crystal structures, while SEM and EDS techniques were used to study the surface morphology and chemical compositions. The dielectric properties of the samples were measured at different frequencies and it was found that they increased with temperature and humidity. Barium ferrite humidity sensors were also created, showing a higher sensitivity for BaFe12O19 compared to BaFe2O4.