Influence of electrode contact arrangements on Polarisation-Electric field measurements of ferroelectric ceramics: A case study of BaTiO3

A range of partial top full bottom electrodes are used to explore the use of bi-polar Polarisation-Electric field ( P – E ) measurements to quantify recoverable energy ( W rec ), energy loss ( W loss ) and the efficiency ( η ) of ferroelectric BaTiO 3 ceramics. The values obtained are dependent on the ratio of sample thickness ( S ) and top contact radius ( r ). With increasing S / r from 0.17 to 1.96 the P – E responses become increasingly distorted and broader. Measurements show W rec increases by a factor of ∼1.4 but W loss increases by a factor of ∼7 with η decreasing from ∼29% to 8%. Finite element modelling was used to simulate the experimental set-up of the sample/electrode arrangements using the Jiles-Atherton model to replicate the ferroelectric behaviour of BaTiO 3 . These models demonstrate the experimentally applied electric field using a simple geometric correction for sample thickness is an underestimation of the actual field experienced by the material under the top contact at high S / r values. We stress the importance of reporting the contact sizes and thicknesses of samples when using P – E measurements to assess W rec , W loss and η in non-linear dielectric materials . This will allow a fairer comparison of performances between various types of materials being considered for high-energy-density ceramic capacitors .