Study on Ba0.5Sr0.5TiO3 thin films grown at a low temperature applicable to microwave tunable devices

Abstract

Ba0.5Sr0.5TiO3 (BST-0.5) thin films of thickness 300 nm were deposited on MgO(001) single crystalline substrates by on-axis rf magnetron sputtering at 650 degreesC. X-ray diffraction data indicate that the BST-0.5 thin films are epitaxially grown on MgO substrates. The orientation relationships are found to be BST-0.5(001)//MgO(001) and BST-0.5[100]//MgO[100]. The stoichiometriy of BST-0.5 thin film is confirmed by Rutherford backscattering. For a stoichiometric BST-0.5 film, the typical dielectric tunability and dielectric loss measured at room temperature and 1 MHz are 33.7% and 0.0057, respectively.