Electrical properties of Al-doped oxyapatites at intermediate temperature

Effect of Sr and Al or Fe co-doping on the sinterability and conductivity of lanthanum silicate oxyapatite electrolytes for solid oxide fuel cells

“…In addition, a small tail or arc at low frequencies (below 100 Hz) is most likely related to the electrode interface reaction. The impedance responses for LSO, LSSAO and LSSFO are dominated by the high and medium frequency arcs, indicating the dominance of the grain bulk and grain boundary resistances to the oxide ion conductivity of the oxyapatite electrolytes, similar to the previous studies [37,43,48,49]. The impedance arcs at the high and medium frequencies of LSO are substantially bigger than that of LSSAO and LSSFO sintered under the identical conditions.…”

Synthesis and characterization of Zr0.85Y0.15O1.925-La9.33Si6O26 composite electrolyte for application in SOFCs

“…The conductivities of YSZ with 8 mol% Y 2 O 3 are 0.16 S/cm at 1000 ℃ and 0.027 S/cm at 800 ℃ [12,13]. Meanwhile, the apatite-type lanthanum silicates such as La 9.33 Si 6 O 26 (LSO) exhibit high chemical and structural stability at high temperatures, and have high oxygen ion transference number over a wide range of oxygen partial pressures [14][15][16][17]. The investigation of the apatite lanthanum silicates has attracted much attention recent years, although the ionic conductivity needs to be improved further.…”

Sinterability and conductivity of barium doped aluminium lanthanum oxyapatite La9.5Ba0.5Si5.5Al0.5O26.5 electrolyte of solid oxide fuel cells

“…In particular, an enhancement of the sinterability and ionic conduction was found in aluminium lanthanum oxyapatite, La 9.33+x/3 Si 6−x Al x O 26.5 [6,[20][21][22]. Doping of La 10−x (Si,Al) 6 O 26±ı with iron increased the total conductivity and sinterability [22][23][24][25][26]. The studies show an enhancement of the ionic conduction in the La 10−x (Si,Al) 6 O 26±ı series, where Al doping is compensated by the La-site vacancies without oxygen content variations [6,22,24] or the oxygen excess without La-cation vacancies [25,27].…”

“…Doping of La 10−x (Si,Al) 6 O 26±ı with iron increased the total conductivity and sinterability [22][23][24][25][26]. The studies show an enhancement of the ionic conduction in the La 10−x (Si,Al) 6 O 26±ı series, where Al doping is compensated by the La-site vacancies without oxygen content variations [6,22,24] or the oxygen excess without La-cation vacancies [25,27]. Experiments on alkaline earth doping studies in samples containing oxygen excess show that the conductivity of barium doped La 9 Ba(SiO 4 ) 6 O 2.5 , which is cation stoichiometric but contains an oxygen excess, is high [28][29][30].…”