TY - JOUR
T1 - Properties of Modified Anodic‐Spark‐Deposited Alumina Porous Ceramic Films as Humidity Sensors
AU - Chen, Zhi
AU - Jin, Mao‐Chang ‐C
AU - Zhen, Chao
AU - Chen, Guan‐Hua ‐H
PY - 1991/6
Y1 - 1991/6
N2 - α‐Alumina films formed by anodic spark deposition in the melt of NaHSO4‐KHSO4 mixture (200°C) exhibited a porous structure. It has been found that the porosity and amount of α‐phase varied with anodic current density. By electrical measurements, films were found to exhibit a continuous open‐pore structure, causing failure of humidity sensors. This problem can be overcome by reanodization of the anodicspark‐deposited alumina films in either borax aqueous solution or sulfuric acid solution for a short time to form an effective barrier layer at the pore base. The modified anodic‐spark‐deposited alumina films showed highly sensitive response to water vapor change in the range of −76° to +20°C dew point with much improved long‐term stability. The humidity characteristics of the α‐alumina films were qualitatively explained in terms of the BET theory and condensation theory.
AB - α‐Alumina films formed by anodic spark deposition in the melt of NaHSO4‐KHSO4 mixture (200°C) exhibited a porous structure. It has been found that the porosity and amount of α‐phase varied with anodic current density. By electrical measurements, films were found to exhibit a continuous open‐pore structure, causing failure of humidity sensors. This problem can be overcome by reanodization of the anodicspark‐deposited alumina films in either borax aqueous solution or sulfuric acid solution for a short time to form an effective barrier layer at the pore base. The modified anodic‐spark‐deposited alumina films showed highly sensitive response to water vapor change in the range of −76° to +20°C dew point with much improved long‐term stability. The humidity characteristics of the α‐alumina films were qualitatively explained in terms of the BET theory and condensation theory.
KW - alumina
KW - anodes
KW - electrical properties
KW - films
KW - humidity
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U2 - 10.1111/j.1151-2916.1991.tb04106.x
DO - 10.1111/j.1151-2916.1991.tb04106.x
M3 - Article
AN - SCOPUS:0006298904
SN - 0002-7820
VL - 74
SP - 1325
EP - 1330
JO - Journal of the American Ceramic Society
JF - Journal of the American Ceramic Society
IS - 6
ER -