Influence of interface structure on microstructure and dielectric properties of bismuth magnesium niobate thin films

摘要

Bismuth magnesium niobate (Bi3/2MgNb3/2O7, BMN) thin films were prepared on bare SiO2/HR-Si and Pt/TiO2/SiO2/HR-Si substrates by using sol-gel spin coating technique followed by rapid thermal annealing process. The influence of the interface on crystalline structure and tunable dielectric properties of the two types of BMN films were investigated. It was found that the BMN films prepared on SiO2/Si substrate with a BMN/SiO2 interface structure had higher orientation and better crystallinity. The deposited BMN thin films with a BMN/SiO2 interface structure exhibited superior tunability of 52.5%, while it showed a relative small tunability value of the film with BMN/Pt interface structure. It suggests that the interface state between the films and substrates, electric field distribution, and orientation degree are responsible for the impacts on the microstructure and tunable dielectric properties of the BMN thin films.