Vibrational Properties of Protons in Hydrated BaInxZr1-xO3-x/2
Artikel i vetenskaplig tidskrift, 2005

We investigate the local proton dynamics in the proton conducting hydrated perovskite system BaInxZr1-xO3-x/2 (x=0.25-0.75) using infrared spectroscopy and first-principles calculations. We show that oxygen vacancies and dopant atoms in the vicinity of the proton tilt the proton toward a neighboring oxygen creating strongly hydrogen-bonded configurations. This is manifested as a strong redshift of the O-H stretch band in the infrared absorption spectrum. We also find considerable fluctuations of the nearest and next-nearest oxygen-proton distances with time, resulting in additional spectral broadening. By comparing the frequencies of computed O-H stretch modes we can relate specific local configurations to different parts of the broad O-H stretch band. Even though hydrogen-bonded configurations favor proton transfer they hinder the long-range migration by decreasing the reorientational rate. Thus, in order to optimize the proton mobility it is important to avoid extreme configurations caused by either oxygen vacancies or dopant atoms in the perovskite structure.

Författare

Maths Karlsson

Chalmers, Teknisk fysik

Mårten Björketun

Chalmers, Teknisk fysik, Material- och ytteori

Per G. Sundell

Chalmers, Teknisk fysik, Material- och ytteori

Aleksandar Matic

Chalmers, Teknisk fysik

Göran Wahnström

Chalmers, Teknisk fysik, Material- och ytteori

Dennis Engberg

Chalmers, Teknisk fysik, Kondenserade materiens fysik

Lars Börjesson

Chalmers, Teknisk fysik, Kondenserade materiens fysik

Istaq Ahmed

Chalmers, Kemi- och bioteknik

Sten Eriksson

Chalmers, Kemi- och bioteknik

Pedro Berastegui

Chalmers, Kemi- och bioteknik

Physical Review B - Condensed Matter and Materials Physics

1098-0121 (ISSN)

Vol. 72 1-7

Ämneskategorier

Den kondenserade materiens fysik

DOI

10.1103/PhysRevB.72.094303