Structure and dielectric properties of (Na_(0.5)Bi_(0.5))TiO_3-SrTiO_3 thick films derived from polyvinylpyrrolidone-modified chemical solution

摘要

In this work, 1.5-μm(1 - x%)(Na_(0.5)Bi_(0.5))TiO_3-x%SrTiO_3 (abbreviated as NBT-xST,x = 0,5,10,30 and 50) thick films were successfully fabricated on LaNiO_3/Si (100) substrate by using a polyvinylpyrrolidone-modified chemical solution route. The effects of the substitution of ST on the microstructure and dielectric properties of the thick films were investigated in detail. It was found that the addition of ST could enhance the dielectric tunable properties and decrease the dielectric losses. The dielectric tunability for all the samples was higher than 30 %, and the maximum value of about 53 % was obtained in NBT-30ST film. Moreover, the substitution of ST improved the value of figure of merit of the thick film. These results indicate that NBT-ST thick films might be one of the promising environmentally friendly lead-free materials for dielectric tunable capacitor applications.