Multicomponent oxides in oxygen potential gradients

How Is Oxygen Incorporated into Oxides? A Comprehensive Kinetic Study of a Simple Solid‐State Reaction with SrTiO3 as a Model Material

“…Whereas the first term is proportional to an inverse chemical resistance, the latter term is the inverse of a "chemical capacitance", [94] which describes the materials ability to accommodate changes in oxygen stoichiometry upon a change in pO 2 . (Note that the same capacitive term appears in Equation (40) 31) and the related term in Equation (23). [99] In the presence of redox-active centers, a "trapping factor" 0 c 1 is included…”

Materials in thermodynamic potential gradients

“…First, Schmalzried and Laqua [26] observed the formation of a multiphase layer in the system NiO-TiO 2 after exposure of a single-phase NiTiO 3 -crystal to an oxygen potential gradient. While (Ni,Ti)O is formed at the high-oxygen potential side, TiO 2 was found at the low-oxygen potential side of the crystal.…”

Ageing of solid electrolytes and electrode materials in electrochemical devices

“…The knowledge of the microstructure and composition of these interfaces and their evolution as a function of time is then crucial to be able to control the ageing of the electrochemical cells and to optimize their operation conditions. This paper reviews the principle of the constituent redistribution across the samples, the so-called kinetic demixing process, which can occur in a multicomponent compound exposed to a "generalized" thermodynamic potential gradient [12][13][14][15][16][17][18]. Emphasis is given to the behavior of solid electrolytes, mixed ionic conducting compounds and semiconducting oxides used as electrode materials, in the presence of a chemical potential gradient, an applied electrical field or a stress gradient.…”