Structural and conductivity properties of K doped Ba 4 Ca 2 Nb 2 O 11 (BCN) complex perovskite for energy applications

Structure and electrical conductivity properties of K doped Sr1−xKx(Sr0.50Nb0.50)O2.75−δ complex perovskites

“…Perovskites (general formula ABO 3 ) is a class of complex oxides that can incorporate large number of point defects such as oxygen vacancies and protons that compensate dopants or part of inherent off-stoichiometry. Among perovskites, complex perovskite of type A 3 (B 1+x B′ 2−x )O 9−3x/2 where A, B= divalent alkaline earth metals and B′=pentavalent Nb, Ta is an important class of model materials for proton and oxide ion conduction [1,2].…”

“…Among perovskites, complex perovskite of type A 3 (B 1+x B′ 2−x )O 9−3x/2 where A, B= divalent alkaline earth metals and B′=pentavalent Nb, Ta is an important class of model materials for proton and oxide ion conduction [1,2]. In such compositions when B and B' cation ratio is 1:2 (A 3 B 1 B' 2 O 9 ), the material exhibits trigonal crystal structure with no structural oxygen vacancies, wheras the composition with 1:1 ordered (A 4 (B 2 B 2 ′)O 11 ) B cation sublattice exhibits a face centered cubic structure with inherent structural oxygen vacancies [2,3]. In perovskite structure both A and B sub-lattices can adopt cations with different valence and size because of their high tolerance resulting in the formation of various types of superstructures [3,4].…”

“…In such compositions when B and B' cation ratio is 1:2 (A 3 B 1 B' 2 O 9 ), the material exhibits trigonal crystal structure with no structural oxygen vacancies, wheras the composition with 1:1 ordered (A 4 (B 2 B 2 ′)O 11 ) B cation sublattice exhibits a face centered cubic structure with inherent structural oxygen vacancies [2,3]. In perovskite structure both A and B sub-lattices can adopt cations with different valence and size because of their high tolerance resulting in the formation of various types of superstructures [3,4]. Perovskite materials that are capable of protonic and ionic conductivity are potential candidates for electrolytes in sensors, batteries, fuel cells, electrolysers etc [5][6][7].…”