Narrow Results

The dielectric properties of Ba_0.6Sr_0.4TiO₃ (BST) thin films deposited using SrRuO₃ (SRO) materials as bottom electrode were compared with those of the films grown using La_0.5Sr_0.5CoO₃ (LSCO) materials as bottom electrode. X-ray diffraction scanning revealed that the two kinds of films could be epitaxially grown in pure single-oriented perovskite phases and atomic force microscopy showed that the root mean square roughness of BST/SRO films were similar to BST/LSCO films. The dielectric properties of the BST/SRO and BST/LSCO thin films were measured at 10 kHz and 300 K with a parallel-plate capacitor configuration. Compared with BST/LSCO, the dielectric tunability for BST/SRO films slightly decreased, while the loss decreased synchronously. The figure of merit factor value increases from 25.67 for BST/LSCO films to 48.76 for BST/SRO films under an applied voltage of 6 V. The leakage current density of the thin films at a positive voltage of 2 V decreases from 2.41 × 10^-7A/cm² for BST/LSCO to 8.41 × 10^-8A/cm² for BST/SRO. This phenomenon is ascribed to the smaller strain induced in BST/SRO materials.