Oxygen diffusion in BaTiO3 ceramic

Abstract

High resistivity diffusion layers are formed by reoxidation between 380 and 750 °C in reduced BaTiO3 ceramic. The potential distribution is measured with an applied voltage at these samples. In addition, observations with the polarizing microscope, resistance and gravimetric measurements are made. The results show that the diffusion of oxygen vacancies is hindered by grain boundaries. The quantities controlling the diffusion mechanism, such as the grain boundary diffusion velocity and the effective diffusion coefficient at longer diffusion distances, are determined experimentally.

Electrical Properties of Cerium‐Doped BaTiO3

“…In addition to this effect, the decrease in grain size can be taken into consideration for degradation since grain boundaries play an important role in impeding the diffusion of oxygen vacancies. 34 Waser has reported the Ce-donor contribution to the degradation behavior of Ce-doped BaTiO 3 . 29 Such a beneficial effect is possible only in the case of metal vacancy compensation in Ce-doped BaTiO 3 , however.…”

Stabilization and Memory of the Domain Structures in Barium Titanate Ceramics: Microstructural Observation

“…The redistribution of oxygen vacancies at 1000°C is therefore expected to be relatively rapid. On the other hand, the migration distance of oxygen vacancies at 500°C for 1 h determined by using a reported diffusion coefficient 23,24 was ϳ10 m. Although this value is much smaller than the bandwidth (ϳ50 m), it may be too excessive compared to the thickness of the space charge layer. At present, this point is not clearly understood.…”

Electrical Degradation and Thermally Stimulated Depolarization Current of Ho-doped BaTiO3 with Excess BaO

“…[19][20][21] If the oxygen vacancies are the main charge carrier in Ba(Ti 1Àx Ho x )O 3À0:5x , the mobility of oxygen vacancies is calculated using the following equation. 1,46)…”