Shah, Jyoti and Kotnala, R. K. (2012) Humidity sensing exclusively by physisorption of water vapors on magnesium ferrite. Sensors and Actuators B: Chemical, 171. pp. 832-837. ISSN 0925-4005

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Abstract

Water vapor adsorption phenomenon on magnesium ferrite surface has been analyzed by determining binding energy involved in adsorption of water vapor. Activation energy for charge conduction has been calculated by fitting Arrhenius equation using temperature dependent (25-45 degrees C) conductivity data in the range for 0-90%RH. Nominal change in activation energy observed with increasing humidity. Clausius-Clapeyron heat equation has been used to calculate the isosteric heats of adsorption utilizing the equilibrium data of the isotherms measured for 25-45 degrees C. The results have exhibited a decrease in heat of adsorption from 0.14 eV at 10%RH to 0.02 eV for 90%RH. While binding energy computed has been found less than 0.2 eV supporting prominent physisorption of water vapors on porous magnesium ferrite. Also, complete recovery of conductivity values in adsorption-desorption curve confirms the physisorption of water vapors. The electrical conduction mechanism in magnesium ferrite with changing humidity has been analyzed by impedance spectroscopy.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s Elsevier.
Subjects:	Chemistry > Analytical Chemistry Electrochemistry Instruments/ Instrumentation
Divisions:	UNSPECIFIED
Depositing User:	Users 27 not found.
Date Deposited:	12 Mar 2020 11:25
Last Modified:	12 Mar 2020 11:25
URI:	http://npl.csircentral.net/id/eprint/3540

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