Gas sensitive performance and mechanism of multiferroic BiFeO3 under thermal-magnetic synergetic excitation

In this study, multiferroic BiFeO3 particles with size of similar to 50 nm and good crystallinity were prepared via a simple sol-gel method and annealing. And the volatile organic compounds (VOCs) sensing properties of BiFeO3 sensor were measured under both traditional thermal excitation and synergetic thermal-magnetic excitation. In particular, auxiliary magnetic field was first introduced into testing environment. The results shows that the optimum operating temperature of the sensor decreases 10celcius by introducing magnetic field, and the sensor shows three times faster response speed and diverse selectivity with best response to n-butanol under thermal excitation while butanone under thermal-magnetic excitation. In addition, the sensor has response value of 1.25 to 1 ppm n-butanol, indicating the possibility of detecting low concentration of toxic gases. The effect of magnetic field on multiferroic BiFeO3 sensor can be divided into three aspects: decrease of defects on domain wall, excitation of testing gas molecules with asymmetry electron cloud distributions and activation of surfaceabsorbed oxygen species with unpaired electrons.

Automated summary

Multiferroic BiFeO3 particles with size of about 50 nm and good crystallinity were prepared via a simple sol-gel method and annealing. The VOCs sensing properties of BiFeO3 sensor were tested under both traditional thermal excitation and synergetic thermal-magnetic excitation, and the results showed improved performance under the latter condition. The effect of magnetic field on the sensor can be attributed to decreased defects on domain walls, excitation of gas molecules, and activation of surface-absorbed oxygen species.