Structural, optical and electrical properties of sol–gel derived (Ba0.6Sr0.4) (NixTi1−x)O3 thin films

The influence of Ni doping on the structural, optical and electrical properties of sol–gel routed (Ba0.6Sr0.4) (NixTi1-x)O3 (x=0.014, 0.027, 0.041) thin films on quartz and stainless steel substrates has been investigated. The XRD analysis indicates that the crystallite size of the material increases with dopant concentration. The FE-SEM analysis indicates that surface morphology varies with dopant concentration. The Ni concentration of 0.041 M is the optimum value for denser, smoother and higher crystallite size. Dielectric properties were investigated as a function of frequency. Dielectric constant and dielectric loss were 1842 and 0.016% at 100 kHz respectively and the transmittance was 70%. The dielectric constant of the film increases with increasing value of the dopant concentration whereas the dielectric loss, the tunability, figure of merit and transparency of the film decreases with increasing value of the dopant concentration. The UV–vis transmission spectrum analysis shows that the band gap of the film decreases with increasing value of the dopant concentration. Correlation of the material properties suggests that the 0.041 M Ni doped thin film was optimal choice for the tunable device applications.