Realization of an H2/CO Dual-Gas Sensor Using CoPd Magnetic Structures

Jaw-Yeu Liang¹, Yu-Jung Chou², Chiao-Wen Yin², Kuan-Wen Chang^2*, Wen-Chin Lin³, Hong-Ji Lin⁴, Po-Wen Chen⁵, Yuan-Chieh Tseng^1,2

¹Graduate Degree Program of Science and Technology of Accelerator Light Source, National Chiao Tung University, Hsinchu, Taiwan
²Department of Materials Science & Engineering, National Chiao Tung University, Hsinchu, Taiwan
³Department of Physics, National Taiwan Normal University, Taipei, Taiwan
⁴National Synchrotron Radiation Research Center, Hsinchu, Taiwan
⁵Physics Division, Institute of nuclear energy research, Taoyuan, Taiwan

* Presenter:Kuan-Wen Chang, email:aqsder55255.mse06g@g2.nctu.edu.tw

We demonstrated the successful application of CoPd magnetic devices in single (H2) and dual (H2 and CO) gas detection by varying the thin-film structure. The anomalous Hall effect (AHE) provided the read-out signal of the devices. The dual-gas sensor was particularly useful for examining whether methane reformation by steam was completed during H2 production where CO is a byproduct. Through in situ Fourier transform infrared (FTIR) and X-ray absorption spectroscopy, we discovered that H2 detection involved a charge-transfer effect between Co and Pd for both multilayer and alloy structures; however, CO detection was associated with a surface-adsorption process, which only occurred in the alloy structure. The proposed devices demonstrated performances exceeding those of current commercial models (solid-state based) regarding power consumption (<5mW) because they were not required to undergo a heating process. An Arduino prototype platform was employed to test the modularization of the device, and adequate feasibility was demonstrated.

Keywords: Spintronics, Anomalous Hall effect, Dual-gas detection