Gas Adsorption Magnetic Variation Effect Enhanced Room‐Temperature NO 2 Sensing with Fe 3 GaTe 2

Abstract Achieving high‐performance, low‐power gas detection at room temperature is critical to safety and energy efficiency, and the key is to deeply explore the interaction mechanisms between sensitive materials and gases. In this work, a magnetic field‐assisted strategy is developed to achieve high‐performance, low‐power NO 2 sensing with the Fe 3 GaTe 2 at room temperature. Fe 3 GaTe 2 nanoflakes are obtained from green solvents using ultrasound‐assisted liquid phase exfoliation. The experimental results confirming that the Fe 3 GaTe 2 nanoflakes sensor demonstrates an excellent response (S = 16 for 10 ppm NO 2 , 1.4 times higher than that without magnetic field), a lower actual detection limit (50 ppb) and a low‐power consumption (0.25 nW) under 21 mT magnetic field at room temperature. Combining theoretical calculations and quasi in situ XPS, it is indicated that Fe is the main electron donor and serves as the main response site for NO 2 . Magnetic field‐enhancing effect for gas sensing is revealed via comparing the in situ field‐dependent magnetization curves of Fe 3 GaTe 2 in air and NO 2 . It is found for the first time that the enhancement of gas sensing is mainly attributed to the gas adsorption magnetic variation effect (GAMVE) which generates in NO 2 . This study provides a strategy of GAMVE‐driven sensing for next‐generation gas sensors.