TY - JOUR
T1 - Study of Xα - Fe2O3 - (1 - X)ZrO2 solid solution for low-temperature resistive oxygen gas sensors
AU - Cao, Wenqing
AU - Tan, Ooi Kiang
AU - Zhu, Weiguang
AU - Pan, Jisheng S.
AU - Bin, Jiang
PY - 2003/8
Y1 - 2003/8
N2 - A noble type of oxygen-sensitive and electrical-conductive material, ZrO2-based with α - Fe2O3 thick-film gas sensor, was investigated for low operating temperature. Amorphous-like solid solutions of xaα - Fe2O3 - (1 - x)ZrO2 powders were derived using the high-energy ball milling technique, and their physical and microstructural properties were characterized from DTA, XRD, TEM, and XPS. The oxygen gas-sensing properties of the screen-printed thick-film gas sensors fabricated from such mechanically-alloyed materials were characterized systematically. Very good sensing properties were obtained with a relative resistance value of 82 in 20% oxygen, and at a low operating temperature of 320 °C. AC impedance spectra and thermally stimulated current were characterized to investigate the conduction properties of the solid solution, 0.2α - Fe2O3 - 0.8ZrO2, in air and nitrogen (carrier gas), respectively. It was found that the Arrhenius plots of σT versus 1000/T have two distinct gradients corresponding to two activation energies in the high and low temperature regions. The transition temperature occurs at about 320 °C that corresponds to an optimal operating temperature of the gas sensor. It is believed that the high oxygen vacancy concentration present in the solid solution, 0.2α - Fe2O3 - 0.8ZrO2, and the dissociation of the associated oxygen vacancy defect complexes at 320 °C are the critical factors for the high relative resistance to oxygen gas at low operating temperature.
AB - A noble type of oxygen-sensitive and electrical-conductive material, ZrO2-based with α - Fe2O3 thick-film gas sensor, was investigated for low operating temperature. Amorphous-like solid solutions of xaα - Fe2O3 - (1 - x)ZrO2 powders were derived using the high-energy ball milling technique, and their physical and microstructural properties were characterized from DTA, XRD, TEM, and XPS. The oxygen gas-sensing properties of the screen-printed thick-film gas sensors fabricated from such mechanically-alloyed materials were characterized systematically. Very good sensing properties were obtained with a relative resistance value of 82 in 20% oxygen, and at a low operating temperature of 320 °C. AC impedance spectra and thermally stimulated current were characterized to investigate the conduction properties of the solid solution, 0.2α - Fe2O3 - 0.8ZrO2, in air and nitrogen (carrier gas), respectively. It was found that the Arrhenius plots of σT versus 1000/T have two distinct gradients corresponding to two activation energies in the high and low temperature regions. The transition temperature occurs at about 320 °C that corresponds to an optimal operating temperature of the gas sensor. It is believed that the high oxygen vacancy concentration present in the solid solution, 0.2α - Fe2O3 - 0.8ZrO2, and the dissociation of the associated oxygen vacancy defect complexes at 320 °C are the critical factors for the high relative resistance to oxygen gas at low operating temperature.
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U2 - 10.1109/JSEN.2003.815787
DO - 10.1109/JSEN.2003.815787
M3 - Article
AN - SCOPUS:3042780045
SN - 1530-437X
VL - 3
SP - 421
EP - 434
JO - IEEE Sensors Journal
JF - IEEE Sensors Journal
IS - 4
ER -