This document discusses barium zirconate, including its perovskite structure and applications as an electrolyte and electrode material in intermediate temperature solid oxide fuel cells. It is doped with Y2O3 to create oxygen vacancies. The document covers the advantages of high stability and reduced fabrication problems between 600-800°C, as well as the disadvantage of difficult sintering. It describes the sample preparation process and characterization techniques to analyze phase formation, density, microstructure. Results show single phase formation but low density without ZnO additive, which enables 92-94% density.

2. CONTENTS
 Doped Barium Zirconate
 Applications, advantages & disadvantages of BZY
 Sintering
 Sample Preparation
 Characterization
 Results and Discussion
 Conclusion

3. BARIUM ZIRCONATE
Pervoskite structure
 When Barium Zirconate (BZ) is doped with Y2O3, oxygen vacancies are formed.
Y2O3 + BaZrO3 2YZr’ + 3Oox + Vooo

4. APPLICATIONS OF BZY
 It is used as electrolyte and electrode material in
Intermediate Temperature Solid Oxide Fuel Cell
(IT-SOFC).

5. ADVANTAGES OF BZY
 High stability with sufficient proton conductivity in
the temperature range of 600-800o C
 Greatly reduces material & fabrication problems
 Improves cell reliability during prolonged operations
 Stable in CO2 and H2O containing atmosphere

6. DISADVANTAGES OF BZY
 Yttria doped barium zirconate material is difficult to
sinter

7. SINTERING
 Sintering simply means “coalescence of powder at
elevated temperatures.”
 The driving force operating during sintering is the
reduction in surface energy.

8. SINTERING
 Various atomic mechanisms:
1. Evaporation – Condensation (path 1)
2. Surface diffusion (path 2)
3. Volume diffusion (path 3)
4. Grain boundary diffusion (path 4)

9. SINTERING STAGES
 An interval of geometric change in which pore shape is totally defined
(such as rounding of necks during the initial stage sintering) or an
interval of time during which the pore remains constant in shape while
decreasing in size

10. SAMPLE PREPARATION
 Solid-state method
 Raw materials: BaCO3 , ZrO2 , Y2O3
 Weighing and mixing/grinding
 Calcination
 Pelletization (uniaxial and cold isostatic pressing)
 Solid state sintering

11. CHARACTERIZATION
 Phase formation
 Density
 Sintering
 Microstructural studies

12. RESULTS & DISCUSSIONS
1. XRD
200
1300
1350
1400
150
Intensity (A.U)
100
50
0
20 30 40 50 60
2

13. RESULTS & DISCUSSIONS
2. PARTICLE MORPHOLOGY & PARTICLE SIZE DISTRIBUTION
 Shape not exactly spherical
 Paricle size varied from 0.205 µm to 1.405 µm
 Average particle size 0.649 µm

14. RESULTS & DISCUSSIONS
3. SINTERING
 Dilatometry Temperature Vs Shrinkage
0
Shrimkage (in %)
-2
-4
-6
0 700 1400
O
Temperature (in C)
maximum shrinkage was 5.36 % at 1556o C

15. RESULTS & DISCUSSIONS
3.SINTERING
 Densification
 Low density
 Grain size was 200 – 500 nm
 Single phase formation had taken place

16. RESULTS & DISCUSSIONS
4. DENSIFICATION USING ZnO
By using ZnO, 92 – 94 % density was obtained.

17. CONCLUSION
 Single phase formation
 BZY couldn’t be sintered properly even at 1550o C
 ZnO helps in sintering

18. THANK YOU!!!