Influence of annealing time on microstructure and dielectric properties of (Ba 0.3 Sr 0.7 )(Zn 1/3 Nb 2/3 )O 3 ceramic thin films prepared by sol–gel method

(Ba 0.3 Sr 0.7 )(Zn 1/3 Nb 2/3 )O 3 dielectric ceramic thin films were fabricated on Si(100) substrates by sol–gel method followed by annealing in O 2 atmosphere at 900 °C for 5, 15, 30, and 45 min. Results show that the surface morphologies of the samples are crack free and compact with well-crystallized structures. The grain sizes of the thin films increase with increased annealing time from 5 to 30 min. Thin films annealed for 30 min possess the minimum root–mean–square (RMS) value of roughness and the highest crystallinity among all samples as well as the best dielectric properties. Thus, 30 min is the optimal annealing time.