Growth of Bi_(1.5)MgNb_(1.5)O_7 thin films on Pt/Ti/SiO_2Si substrates by RF magnetron sputtering

摘要

In this letter, bismuth magnesium niobate (Bi_(1.5)MgNb_(1.5)O_7, BMN) thin films were deposited on Pt/ Ti/SiO_2/Si substrates by using radio-frequency magnetron sputtering at various substrate temperatures. Based on the phase compositions and microstructures of these samples, we discussed the nucleation and growth of the BMN thin films and how the substrate temperature influenced these processes. The thin film begins to crystallize at 450 ℃, and the annealed films were all composed of the cubic py-rochlore phase with a strong (222)-preferred orientation. The film deposited at 450 ℃ exhibited a large dielectric constant of 173, and a tunability of 26.6 % was obtained at a max dc bias field of 0.8 MV/cm.