Barium Zirconate Titanate Electrical Properties Of Thin Films Doped With Cobalt-chromium

Barium zirconate titanate (BaZrxTi1-xO3, BZT) thin film is an infinite solid solution of barium titanate and barium zirconate. Its dielectric and ferroelectric properties are not only related to the proportion of zirconate and titanate, but also related to different kinds of doping mechanisms closely. The main aim of paper is to study the influence of components ratio and doping elements on dielectric constant, the dielectric loss and the leakage current of BZT thin film. The working process is as follows:lanthanum nickel acid (LaNiO3, LNO) thin film and BZT thin film have been prepared on the silicon wafer in sol-gel process orderly.and then some Ag point-electrodes are prepared by magnetron sputtering method on the BZT thin film. The main points are as follows:First of all,LNO thin film was prepared on the silicon wafers(100),which was used as the bottom electrode. We got the smooth and good compact thin LNO film By adjusting the content of solvent and complexant. heating rate and temperature. The thickness of the LNO film was measured by ellipsometer which showed the film’s thickness was233nm and the refractive index was2.3.The resistivity was measured by4-point probes technique.and the value was1.57×10-5Ω·cm.Secondly,different kinds of composition and thickness BZT films were prepared by sol-gel method on the LNO film. After then.some Ag point-electrodes were prepared. Studies have shown that the dielectric constant increases with the content of zirconate increasing.the leakage current is reduced.while the dielectric loss has almost no change. For samples who have same composition,dielectric constants and loss and leakage current are all reduced with the thickness increasing. This is because relaxor phase is much easier to happen with the zirconate content increasing. Select an standard sample as the reference of follow-up work, its thickness is about390nm. electric constant242. dielectric loss0.49while the frequency is equal to300KHz.The leakage current is0.2uA.and the breakdown electric field intensity is about1654KV/cm.Thirdly.different concentration of Co-doped and Cr-doped BZT films were prepared.Experiments show that Co-doped thin films’ dielectric constants increased at the low concentration.while reduced at the high concentration. Co-doping is able to reduce the dielectric loss.dielectric loss and leakage current increased with the Co-doped concentration, and the breakdown electric field intensity reduced, Cr-doped thin films" dielectric constants increased at the low concentration doping.and reduced at the high concentration doping..Both the dielectric losses and leakage current reduced with the Cr-doped concentration increasing, and the breakdown electric field intensity is improved. In this section, different phonomenons are analyzed from the perspective of internal space charge polarization and the "pinning" function of oxygen vacancy and controlling the reduction of Ti4+to Ti3+by doping low chemical valence elements.