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Temperature-Dependent Infrared Spectroscopy of Proton-Conducting Hydrated Perovskite BaInxZr1-xO3-x/2 (x=0.10-0.75)

Maths Karlsson ; Aleksandar Matic (Institutionen för teknisk fysik, Kondenserade materiens fysik) ; Ezio Zanghellini (Institutionen för teknisk fysik, Kondenserade materiens fysik) ; Istaq Ahmed (Institutionen för kemi- och bioteknik, Oorganisk miljökemi)
Journal of Physical Chemistry C (1932-7447). Vol. 114 (2010), 13, p. 6177-6181.
[Artikel, refereegranskad vetenskaplig]

We investigate the temperature dependence of the O-H stretch band in the infrared absorbance spectra of the proton-conducting hydrated perovskites BaInxZr1-xO3-x/2 (x = 0.10-0.75) over the temperature range -160 to 350 degrees C. Upon increasing temperature from -160 to 30 degrees C, we show that there is a redistribution of protons from nonsymmetrical structural configurations, such as Zr-OH-In and Zr-OH-Zr-vacancy, where the degree of hydrogen bonding between the protons and neighboring oxygens is strong, to symmetrical configurations, such as Zr-OH-Zr and In-OH-In, where hydrogen bonding is weaker. Spectra measured at elevated temperatures, 30-350 degrees C, indicate preferential desorption of protons in sites where the degree of hydrogen bonding is strong, and show that the materials gradually dehydrate with increasing temperature. The dehydration rate is found to be highest in the temperature range 275-325 degrees C. Furthermore, the spectroscopic results indicate that strong hydrogen bonding, caused by dopant-induced short-range structural distortions, is favorable for high proton mobility and that the rate-limiting step in the conduction mechanism is the proton transfer between neighboring oxygens.

Denna post skapades 2010-05-05. Senast ändrad 2016-07-06.
CPL Pubid: 121230


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Institutioner (Chalmers)

Institutionen för teknisk fysik, Kondenserade materiens fysik (1900-2015)
Institutionen för kemi- och bioteknik, Oorganisk miljökemi (2005-2014)


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