Sensors and Actuators B Chemical 128 (2007) 124-132 pre-print.pdf (929.55 kB)
Characterisation and humidity-sensing properties of aluminium (oxy)-hydroxide films prepared by cathodically induced precipitation
journal contribution
posted on 2013-01-11, 11:52 authored by Roger J. Mortimer, Russell J. MayesCathodically-induced precipitated aluminium (oxy)-hydroxide films, prepared
using hydrogen-sorbing palladium electrodes, have been characterised and their
humidity-sensing electrical properties studied. Infrared (IR) spectroscopy
demonstrated that the films are hygroscopic, and this property allows their use as the
active component in a humidity sensor. Films formed as bridging precipitates between
twin palladium electrodes were tested for electrical parameter response to relative
humidity changes. A linear correlation with impedance is obtained on application of a
100 mV applied ac signal amplitude at 1 kHz. The linearity of response is comparable
to commercial sensors. Cathodically-induced precipitate films contain 24 wt%
aluminium and 10 wt% sulfate, the balance being oxygen and hydrogen. As-deposited
films are amorphous, but change to a crystalline form after heat treatment at high
temperature. XRD patterns taken as films are heated reveal transformation into γ-
Al2O3, followed by production of α-Al2O3 at temperatures greater than 1100°C. An
electrochemical quartz crystal nanobalance (EQCN) study demonstrated that
dissolution of the precipitate is possible at positive potentials, cycling to which allows
film compaction.
History
School
- Science
Department
- Chemistry
Citation
MORTIMER, R.J. and MAYES, R.J., 2007. Characterisation and humidity-sensing properties of aluminium (oxy)-hydroxide films prepared by cathodically induced precipitation. Sensors and Actuators B: Chemical, 128 (1), pp. 124 - 132.Publisher
© Elsevier B.V.Version
- AM (Accepted Manuscript)
Publication date
2007Notes
This article was published in the journal, Sensors and Actuators B: Chemical [© Elsevier B.V.] and the definitive version is available at: http://dx.doi.org/10.1016/j.snb.2007.05.040ISSN
0925-4005Publisher version
Language
- en