The relationship between oxide-ion conductivity and cation vacancy order in the hybrid hexagonal perovskite Ba₃VWO_8.5

Abstract

Cation ordering in Ba3VWO8.5 disrupts long-range oxygen diffusivity parallel to the c-axis resulting in reduced ionic conductivity.

Structure–property correlation in oxide-ion and proton conductors for clean energy applications: recent experimental and computational advancements

“…Gilane et al applied BVEL to Ba 3 VWO 8.5 (BVWO), which exhibits ordered vacancies on the B2 site. 38 The energy barriers are similar to those of BNMO. However, BVWO showed much lower bulk conductivity than BNMO and BNWO.…”

A pressure induced reversal to the 9R perovskite in Ba3MoNbO8.5

“…The energy barrier for diffusion across O(2) and O(3) sites increases steeply above this point suggesting that the absence of the relaxation energy drives up the energy barriers to migration as the motional enthalpy of ions is increased. The analogous compound, Ba 3 WNbO 8.5 , 26,30 has a low value of s(R) $ 0.047Å and no sizeable E 2 barrier, therefore, it can be ascertained that the E 2 barrier is likely absent for members of the Ba 3 MNbO 8.5 system with s(R) values below 0.07Å. It is also worth noting that there is a steep change in bond angle variances >2.8 GPa.…”

“…Previous BVSE and maximum entropy studies indicate diffusion occurs over the partially occupied face of M(1)O 6 octahedra resulting in the formation of newly coordinated M(1)O 4-5 units. 29,30 The saddle point associated with E 1 corresponds to oxide ion exchange along the connected distribution of O(2)/O(3) oxygen sites, therefore, the magnitude of E 1 will be inuenced by the average distribution of oxygen atoms across these positions. The conductivity of Ba 3 MoNbO 8.5 is known to increase as the ratio of tetrahedra increases.…”

Atomic Structure of the Initial Nucleation Layer in Hexagonal Perovskite BaRuO3 Thin Films

“…[ 2 ] In this regard, hexagonal perovskites provide an excellent platform for the investigation of a myriad of structure‐property relationships. [ 3–6 ]…”