Synthesis of Pure La10-XSrxSi6O27-0.5x Apatites Using an Optimized Sol-Gel Process
The electrical properties were measured as a function of temperature by complex impedance spectroscopy, using a Solartron 1260A frequency response analyzer (FRA) in the frequency range 5 Hz - 15 MHz, under static air. The measurements were performed at the open circuit voltage as well as with an applied AC voltage of 100 mV. The impedance diagrams were recorded from 673 K to 1273 K with thermal steps and stabilization times of about 25 K and 20 minutes respectively. The results show that the ionic conductivity is thermally activated and its value lies between 3×10-5 and 1×10-6 S.cm-1 at 873 K as function of the composition and powder preparation conditions.
Keywords: Sol-gel processes; SOFC; apatite type lanthanum silicates; Sr doping
1. S. Nakayama, et al, Journal of Materials Chemistry 5 (1995) 1801-1805.
2. Claire Bonhomme, et al, Solid State Ionics 180 (2009) 1593–1598
3. Jun Xiang, et al, Electrochimica Acta 153 (2015) 287–294
4. R. Serra, et al, Journal of Alloys and Compounds 536S (2012) S480–S484
5. Janne Patakangas, et al, Journal of Power Sources 263 (2014) 315-331
6. Chieko Yamagata, et al, Materials Research Bulletin 48 (2013) 2227–2231