Influence of Yttrium Concentration on Local Structure in BaZr1-xYxO3-delta Based Proton Conductors
Artikel i vetenskaplig tidskrift, 2017

The evolution of local structure, coordination of protons, and proton conductivity in yttrium-doped barium zirconate, BaZr1-xYxO3-delta (x = 0-0.5), has been investigated using thermal-gravimetric analysis, impedance spectroscopy, and infrared spectroscopy. Low-frequency (50-1000 cm(-1)) infrared absorbance spectra provide evidence of increasing local structural distortions as a function of yttrium concentration as well as subtle differences, mainly linked to the oxygen sublattice, between the dry and hydrated samples. High-frequency (1700-4500 cm(-1)) spectra of the hydrated samples, distinguished by a broad O-H stretch continuum, manifest a varying degree of hydrogen bond interactions between the protons and nearest neighbor oxygens due to the disordered crystal structure with a general weakening in. particular of the strongest hydrogen bonding interactions with increasing dopant levels. It is argued that compositions within the range 0.15 <= x <= 0.3 possess a favorable level of local structural distortions to facilitate high proton conductivity, and this, coupled with a significant proton concentration, may be a factor in explaining the high proton conductivity these phases display.

Improve

Conductivity

Doped Barium Zirconate

Författare

C. W. Mburu

University of Nairobi

Samuel Mwaniki Gaita

Göteborgs universitet

University of Nairobi

Christopher Knee

Göteborgs universitet

Michael J Gatari

University of Nairobi

Maths Karlsson

Chalmers, Fysik, Kondenserade materiens fysik

Journal of Physical Chemistry C

1932-7447 (ISSN) 1932-7455 (eISSN)

Vol. 121 16174-16181

Ämneskategorier

Fysikalisk kemi

DOI

10.1021/acs.jpcc.7b05023