Influence of Yttrium Concentration on Local Structure in BaZr(1-x)Y(x)O(3-δ) Based Proton Conductors

• © 2017 American Chemical Society. The evolution of local structure, coordination of protons, and proton conductivity in yttrium-doped barium zirconate, BaZr 1-x Y x O 3-δ (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.

Ämnesord

NATURVETENSKAP  -- Kemi -- Materialkemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Materials Chemistry (hsv//eng)

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

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