Tunable Magnetoresistive Gas Sensing Enabled by La-Deficient LaFeO<sub>3</sub>
Resistive sensors are widely used to detect gases, but integrating magnetoresistive effects for enhanced selectivity and sensitivity remains largely unexplored. Here we have investigated several magnetic materials in a metal oxide semiconductor (MOS) sensor, showing that iron oxides can exhibit both positive and negative magnetoresponses at relatively low operating temperatures (120-160 °C), with no simple correlation between magnetoresponse and bulk magnetization, leading to the discovery of La<sub>0.8</sub>FeO<sub>3</sub> as an outstanding material for magnetoresistive gas sensing. Under a 0.9 T magnetic field, La<sub>0.8</sub>FeO<sub>3</sub> shows a 134% increase in response to 40 ppm of NO<sub>2</sub> in air. The paramagnetism of oxygen gas is found to provide a substantial magnetosensing contribution, as the use of nitrogen as the background gas diminishes the magnetoresponse of La<sub>0.8</sub>FeO<sub>3</sub> by a factor of 3. Our findings establish magnetic field modulation as a powerful strategy for tuning gas sensor performance, opening new directions in sensing technologies.
Authors
- J. Paul Attfield (ORCID: https://orcid.org/0000-0001-9763-3987)
- Congling Yin (ORCID: https://orcid.org/0000-0002-5525-4345)
- Minghui Yang (ORCID: https://orcid.org/0000-0003-1071-1327)
- Haoming Sun (ORCID: https://orcid.org/0000-0003-0301-7951)
Institutions
- Dalian University of Technology (CN)
- Guilin University of Technology (CN)
- General Research Institute for Nonferrous Metals (China) (CN)
- University of Edinburgh (GB)
Publication Details
- Journal
- ACS Sensors
- Published
- 2025-08-27
- DOI
- https://doi.org/10.1021/acssensors.5c01573
- Citations
- 4
- Primary Topic
- Gas Sensing Nanomaterials and Sensors
- Type
- article
- Field-Weighted Citation Impact
- 2.92
Funders
- National Natural Science Foundation of China
- Engineering and Physical Sciences Research Council
- Fundamental Research Funds for the Central Universities