Magnetic field-enhanced conductometric acetone gas sensing of multiferroic Bi0.92Dy0.08FeO3

While non-contact magnetic fields have been widely employed as stimuli for modulating magnetic, electric, and catalytic properties, their direct influence on gas sensing processes remains unexplored. The renaissance of multiferroics, whose surface electric polarization can be magnetically controlled via intrinsic magnetoelectric coupling effect, offers the possibility to manipulate gas sensing properties through magnetic field. Here, we investigated the effect of the external magnetic field on gas sensing performance using the most representative multiferroic material. Our experimental results demonstrate that the Bi_0.92Dy_0.08FeO₃ sensors exhibit a non-linear magnetic field-controlled acetone sensing performance. When the Bi_0.92Dy_0.08FeO₃ sensor is exposed to a 140 mT magnetic field, its gas response towards 100 ppm acetone rises from 12.7 to 20.3, reaching a 60 % increase. The response time decreases from 53 to 41 s, corresponding to a 113 % increase in reaction rate constant. These improvements are attributed to the magnetoelectric coupling effect, which induces surface uncompensated polarization and enhances domain conductivity, thereby promoting surface oxygen chemisorption and charge carrier transport. Our findings not only advance the fundamental understanding of magnetically tunable gas sensors but also broaden the potential applications of multiferroic materials.