Wongsricha Jurimart, Sreejivungsa Kaniknun, Thanamoon Noppakorn, Harnchana Viyada, Srepusharawoot Pornjuk, Phromviyo Nutthakritta, Jarernboon Wirat, Thongbai Prasit
Giant Dielectric and Computational Design Research Group (GD-CDR), Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand.
Department of Fundamental Science, Faculty of Science and Technology, Surindra Rajabhat University, Surin, 32000, Thailand.
Sci Rep. 2024 Aug 12;14(1):18656. doi: 10.1038/s41598-024-69910-6.
In this study, we investigated the humidity sensing properties of TiO-based ceramics doped with tantalum pentoxide (TaO) and indium tin oxide (ITO). Pure TiO, 1%Ta-doped TiO (1%TTO), 1%ITO-doped TiO (1%ISTO), and 1%(TaO + ITO) co-doped TiO (1%ISTTO) ceramic samples were obtained by sintering at 1200 °C for 3 h. The rutile phase was observed in all samples. The lattice parameters of the single and co-doped samples were larger than those of pure TiO, confirming the substitution of dopants. Porosity was observed in all ceramics. The mean grain sizes of all doped samples were significantly reduced compared to undoped TiO. A homogeneous element dispersion was observed in the 1%TTO and 1%ISTTO ceramics, while segregation particles of related In-rich elements was observed in the 1%ISTO ceramic. Giant dielectric properties were not achieved in any samples due to the porosity. Nevertheless, excluding the undoped TiO, the dielectric properties of all porous ceramics varied significantly with changes in humidity. The 1%ISTTO ceramic demonstrated superior humidity sensing properties, including a low maximum hysteresis error of 3.6% at 10 Hz. In contrast, the 1% TTO and 1% ISTO ceramics showed higher maximum hysteresis errors of 7.2% and 19.8%, respectively. Notably, the response and recovery times were 7.05 ± 0.18 and 2.48 ± 0.39 min, respectively, with good repeatability. This improvement is likely due to the synergistic effect of oxygen vacancies and defects on the surface, enhancing the humidity sensing properties of the 1% ISTTO ceramic, coupled with its optimal microstructure due to its lowest porosity and grain size.
在本研究中，我们研究了掺杂五氧化二钽（Ta₂O₅）和氧化铟锡（ITO）的TiO₂基陶瓷的湿度传感特性。通过在1200℃下烧结3小时获得了纯TiO₂、1%Ta掺杂的TiO₂（1%TTO）、1%ITO掺杂的TiO₂（1%ISTO）和1%（Ta₂O₅ + ITO）共掺杂的TiO₂（1%ISTTO）陶瓷样品。在所有样品中均观察到金红石相。单掺杂和共掺杂样品的晶格参数大于纯TiO₂的晶格参数，证实了掺杂剂的替代。在所有陶瓷中均观察到孔隙率。与未掺杂的TiO₂相比，所有掺杂样品的平均晶粒尺寸均显著减小。在1%TTO和1%ISTTO陶瓷中观察到均匀的元素分散，而在1%ISTO陶瓷中观察到相关富铟元素的偏析颗粒。由于孔隙率，任何样品均未实现巨大的介电性能。然而，除了未掺杂的TiO₂外，所有多孔陶瓷的介电性能随湿度变化而显著变化。1%ISTTO陶瓷表现出优异的湿度传感特性，包括在10Hz时低至3.6%的最大滞后误差。相比之下，1%TTO和1%ISTO陶瓷的最大滞后误差分别较高，为7.2%和19.8%。值得注意的是，响应时间和恢复时间分别为7.05±0.18和2.48±0.39分钟，具有良好的重复性。这种改善可能是由于表面氧空位和缺陷的协同效应，增强了1%ISTTO陶瓷的湿度传感特性，再加上其最低的孔隙率和晶粒尺寸所导致的最佳微观结构。
