Effect of Mg doping on dielectric properties of sol-gel derived (Pb0.7Sr0.3)Mg x Ti1–x O3–x thin film
(Pb0.7Sr0.3)Mg x Ti1–x O3–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 (Pb0.7Sr0.3)Mg x Ti1–x O3–x thin film. Its lattice constant was found to decrease with the increase of x when x < 0.1 and increase when x > 0.1.The crystalline phase formation and the dielectric properties of the (Pb0.7Sr0.3)Mg x Ti1–x O3–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.
KeywordsSol-gel processes PST Thin films Mg doping Dielectric properties
This work is supported by NSFC (Grants Nos. 50372057, 50332030), and the National Key Scientific and Technological Project (Grant No. 2002CB613302), respectively.