The CexTh1-xO2 solid solutions were prepared by citrate sol-gel method, and their structure and reduction properties were studied. XRD shows that solid solution
Polycrystalline Ca2.7-xEr0.3NaxCo4O9+δ (x=0, 0.05, 0.1, 0.15) samples were prepared using a sol-gel process followed by hot-pressing technique sintering and th