Improving conductivity of apatite-type lanthanum silicate by Nd and Zn co-doping

Analysis of the conduction mechanisms of the Ni doped apatite‐type lanthanum silicate electrolyte ceramics synthesized by the combustion method

“…In general, the ions with larger radii are more likely to be doped at the La site, whereas the ions with smaller radii are more generally doped at the Si site. As reported in the literature, the closer is the radius of the doping ion to the radius of the doped ion, the easier is the doping process 7–16 . Nickel is one of the most promisingly active metals with low cost.…”

“…As reported in the literature, the closer is the radius of the doping ion to the radius of the doped ion, the easier is the doping process. [7][8][9][10][11][12][13][14][15][16] Nickel is one of the most promisingly active metals with low cost. As we all know, the radius of Ni 2+ is higher than that of Si 4+ , and the radius of La 3+ is higher than that of Ni 2+ .…”

First-Principles Analysis of the Oxide-Ion Conduction Mechanism in Si-Deficient Lanthanum Silicate Apatite

“…Apatite-type rare-earth silicate (Figure ) was discovered as an oxide-ion conductor by Nakayama et al It has excellent oxide-ion conductivity at intermediate temperatures of less than 700 °C. − Although lanthanum silicate (LSO) undergoes protonation when exposed to water vapor, it can maintain its structural stability, , and thus can be regarded as having better chemical stability in the SOFC operating environment than YSZ. Such properties are advantageous in applications to SOFC and other ion conductor devices.…”

Highly enhanced electrical properties of lanthanum-silicate-oxide-based SOFC electrolytes with co-doped tin and bismuth in La9.33−xBixSi6−ySnyO26

“…5 Several studies reported that by adding dopants to the apatite lattice structures at the La and Si sites, the conductivity can be increased. 5,6 Some of the dopants that have been reported to substitute La and Si in LSO are Sr, 7,9 Ca, 7 Ba, 2,10 Mg, 11 Cu, 12 Co, 13 W, 10 and Ti. 14 Noviyanti et al 15 added 0.5 and 1.0 of Bi dopant at the La site, while Xiang et al 16 reported that 0.5 doping of Sn at the Si site resulted in conductivity values of 2.46 Â 10 À4 S cm À1 at 773 K and 5.71 Â 10 À3 S cm À1 at 1073 K. Whereas various Bi doping at composition of 0.5 # x # 2 on La 10x Bi x (SiO 4 ) 6 O 3 resulted in a conductivity of 2.4 Â 10 À4 S cm À1 at 973 K, 17 Abbassi et al 18 also reported that doping of Bi in CaBaLa 6 Bi 2 (SiO 4 ) 6 O 2 has resulted a conductivity of 2.20 Â 10 À5 S cm À1 at 873 K. However, the simultaneous use of Bi and Sn doping at La and Si sites in the LSO-apatite structure has not been reported before.…”

“…LSO with a hexagonal crystal structure with three possible space clusters namely P 3̄, P 6 3 and P 6 3 / m was first discovered by Nakayama et al 4 The electrolytes of the LSO generally exhibit insufficient conductivity at lower operating temperatures below 973 K. However, the open structure of the LSO allows modification by the doping technique on the La and Si site which makes it possible to obtain sufficient conductivity values at low-temperature operation. 5 Several studies reported that by adding dopants to the apatite lattice structures at the La and Si sites, the conductivity can be increased. 5,6 Some of the dopants that have been reported to substitute La and Si in LSO are Sr, 7,9 Ca, 7 Ba, 2,10 Mg, 11 Cu, 12 Co, 13 W, 10 and Ti.…”