Thickness and dielectric constant of dead layer in Pt/(Ba0.7Sr0.3)TiO3/YBa2Cu3O7-x capacitor

Pt/(Ba0.7Sr0.3)TiO3 (BST)/YBa2Cu3O7-x capacitors were prepared and investigated for the dead-layer (DL) thickness (t(d)) and the DL dielectric constant (epsilon(d)). Based on the series capacitor model, the t(d)/epsilon(d) ratio of 0.066 nm and the bulk BST ferroelectric-layer dielectric constant of 1370 were obtained through the measurements of the capacitance-voltage characteristics. The t(d) x epsilon(d) value of 120 nm was obtained through the measurements of the current-voltage characteristics. Combining these data, the DL thickness and the DL dielectric constant are respectively estimated to be 2.8 nm and 42.6. (C) 2004 American Institute of Physics.