Ion Diffusion Mechanism in Ion-conducting Materials through Neutron Diffractometry

Abstract

Ionic diffusion paths are important for the ion-diffusion mechanism in the ionic conducting ceramic materials. Here we present a brief review on the ionic diffusion paths in some ionic conducting ceramic materials. In the fluorite-structured ionic conducting ceramics such as bismuth oxide-based materials, a similar curved diffusion pathway is observed along the ＜100＞ directions. In the ionic conductors with the cubic ABO₃ perovskite-type structure such as (La_0.8Sr_0.2)(Ga_0.8Mg_0.15Co_0.05)O_3-δ, the mobile ions diffuse along a curved line keeping the interatomic distance between the B cation and O^2- anion to some degree. The structure and diffusion path of K₂NiF_4-type (Pr_0.9La_0.1)₂(Ni_0.74Cu_0.21Ga_0.05)O_4+δ and apatite-type La_9.69(Si_5.70Mg_0.30)O_26.24 are also presented.