CO Sensing Properties of La-added MgFe2O4 Powders.

Autor: Kenji Obata, Shigenori Matsushima
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Zdroj: Sensors & Materials; 2021, Vol. 33 Issue 9,Part 3, p3213-3219, 7p
Abstrakt: La-added MgFe2O4 (MgFe2-xLaxO4, 0.05 ≤ x ≤ 0 .20) and pure MgFe2O4 powders were prepared using a malic acid complex, and their CO sensing properties were examined in dry air in the temperature range of 300-500 °C. It was observed that when the measurement atmosphere was changed from air to CO, the electrical resistance of the MgFe2O4 sensor decreased, whereas that of the MgFe2-xLaxO4 sensor increased, indicating that the MgFe2-xLaxO4 sensor is a p-type semiconductor. It was also observed that the addition of La significantly improved the CO sensitivity of the MgFe2O4 sensor. Among the MgFe2-xLaxO4 sensors examined, the MgFe1.85La0.15O4 sensor exhibited the highest response to CO at 300 °C, and its value was 11.2 times higher than that of the pure MgFe2O4 sensor. However, the MgFe1.85La0.15O4 sensor did not exhibit a rapid response or steady-state electrical resistance in a CO atmosphere at 300 °C. Conversely, at 400 °C, the MgFe1.90La0.10O4 sensor exhibited a higher response to CO than the MgFe1.85La0.15O4 sensor and showed a quick response and a steady-state resistance. Therefore, it can be concluded that the MgFe1.90La0.10O4 sensor exhibited the best CO detection characteristics among the sensors examined. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index