Effects of substrate temperature on the dielectric properties of Bi1.5MgNb1.5O7 thin films derived from pulsed laser deposition

•Bi1.5MgNb1.5O7 thin films were prepared by pulsed laser deposition.•BMN thin film deposited at 700 °C has a medium tunability of 22.1%.•Grown temperature dependence of permittivity and loss tangent was discussed.•The mechanism of the leakage current of the thin films was explained possibly.

The dependence of dielectric properties on the substrate temperature of the Bi1.5MgNb1.5O7 (BMN) thin films prepared on Au-coated Si substrates by the pulsed laser deposition technique has been investigated. It is shown that the substrate temperature has a significant effect on the structural and dielectric properties of BMN thin films. The deposited BMN thin films had a cubic pyrochlore phase when deposited at 600 °C or higher. A BMN thin film with an optimal substrate temperature of 700 °C has a medium dielectric constant of 106, a high tunability of 22.1% and a low loss tangent of 0.003. In addition, the effect of the substrate temperature on the leakage current of the thin films was also discussed.