Oxygen pressure dependence of structure and electrical properties of pulsed laser deposited Ba(Fe1/2Nb1/2)O3 thin films

摘要

The role of oxygen pressure on the microstructure, dielectric properties, and leakage mechanisms of polycrystalline Ba(Fe1/2Nb1/2)O3 thin films grown by pulsed laser deposition was investigated. Strong oxygen pressure dependence of the crystal structure was observed together with the structure distortion. Investigation on the dielectric properties showed the multidispersive relaxation nature for all Ba(Fe1/2Nb1/2)O3 thin films. The conduction properties of Ba(Fe1/2Nb1/2)O3 thin films prepared in various oxygen pressures were also discussed. Space-charge-limited conduction may have a dominant role in the thin films deposited in 1 and 15 Pa oxygen pressure, and for the thin films grown in 10 Pa, the Poole–Frenkel conduction was suggested. While for the thin films deposited in 5 Pa, there was no clear dominant mechanism.