Influence of Sc concentration on transport properties of CaHf1-xScxO3-α

• Published in: Ionics 2021-05, Vol.27 (5), p.2097-2106
• Main Authors: Ding, Yushi, Li, Ying, Gong, Shuo, Huang, Wenlong, Yan, Hao
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Conduction cooling; Crystal lattices; Crystal structure; Doping; Electrochemistry; Energy Storage; Lattice parameters; Optical and Electronic Materials; Original Paper; Perovskites; Proton conduction; Renewable and Green Energy; Transport properties
• ISSN: 0947-7047; 1862-0760
• DOI: 10.1007/s11581-021-03975-5

In this work, a series of CaHf 1-x Sc x O 3-α ( x = 0, 0.10, 0.15, 0.20, and 0.30) perovskite oxides have been prepared by a solid-state reaction. The crystal structure and lattice parameters of the orthogonally-distorted perovskite phases of CaHf 1-x Sc x O 3-α were obtained. The results revealed that Sc-doping could significantly improve the conductivity and proton transport properties of CaHfO 3 . However, at x > 0.2, the conductivity decreased with increase in Sc concentration. CaHf 0.85 Sc 0.15 O 3- α exhibited the highest conductivity among all specimens in the temperature range of 400 to 900 °C. The conduction activation energy of CaHfO 3 significantly decreased with Sc-doping in the range of 0.66 to 1.52 eV. Overall, the CaHf 1-x Sc x O 3-α demonstrated pure proton conduction in the temperature range of 300 to 600 °C under wet 1%H 2 -Ar, whereas the proton relative transport number decreased with increasing temperature to within the range of 600–900 °C. At an optimal Sc concentration of x = 0.1, CaHf 1-x Sc x O 3-α rendered the highest proton transport number.