Effect of Mg doping on dielectric properties of sol-gel derived (Pb0.7Sr0.3)MgxTi1–xO3–x thin film

(Pb 0.7 Sr 0.3 )Mg x Ti 1– x O 3– x ( x = 0 ∼ 0.3) thin films were successfully prepared on ITO/glass substrate by sol-gel technique. The crystalline phase structures were measured through X-ray diffraction (XRD). The dielectric properties were measured by a precision impedance analyzer. Results show that the perovskite phase was stable in (Pb 0.7 Sr 0.3 )Mg x Ti 1– x O 3– x thin film. Its lattice constant was found to decrease with the increase of x when x 0.1.The crystalline phase formation and the dielectric properties of the (Pb 0.7 Sr 0.3 )Mg x Ti 1– x O 3– x thin film depend on Mg doping content. The phase formation ability was decreased below x = 0.1 and then increased above x = 0.1 with the increase in x . The dielectric constant of the thin film is correspondingly changed. The tunabilities of about 35% ∼ 63% were obtained at 10 kHz. The highest tunability and the lowest dielectric loss of the thin films appeared at x = 0.2. The FOM of the thin film with Mg doping of x = 0.2 is about three times higher than that of x = 0.1 under applied frequency of 10 kHz.