Yttrium doped hafnium oxide Hf0.69Y0.31O2-δ used for solid oxide fuel cell electrolytes and electronic materials
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An Yttrium doped hafnium oxide Hf0.69Y0.31O2-δ (YSH orYDH) is obtained by a modified solid state reactionmethod, where freeze drying is implemented to reduce theagglomeration. Refinement result shows that YSH is influorite cubic crystal with lattice parameter a = b = c =5.140674 Å (Figure 1). Based on this, the ionic radius ofY3+ in YSH for 8 coordination is 0.1006 nm, confirms theprevious prediction that it should be smaller than 0.1015nm. The YSH ceramic material with relative density of>97.5% can be obtained by conventional sintering at 1650℃ for 10hrs. Its conductivity is only 3.65×10-5 s cm-1 at700 ℃ (Figure 2), which is too low for solid oxide fuelcell application. However, its high dielectric constant22.03 (Figure 3a, average value, which is 1.4 times largerthan the pure Hafnia) and low dielectric loss over a widefrequency range and DC potential make it very promisingfor the microelectronic device application.
Metallurgy and Metallic Materials
IdentifiersURN: urn:nbn:se:kth:diva-146190OAI: oai:DiVA.org:kth-146190DiVA: diva2:722678
QS 20142014-06-092014-06-092014-06-09Bibliographically approved