Converse flexoelectric coefficient f ₁₂₁₂ in bulk Ba _0.67Sr_0.33TiO₃

The converse flexoelectric effect, referred as the electric field gradient induced strain, widely exists in dielectric materials, but its experimental studies have been reported by few research groups so far. In this Letter, we report our studies on the converse flexoelectric behavior of (Ba _0.67Sr_0.33)TiO₃ ceramics and present the measured value of its flexoelectric coefficient f₁₂₁₂. In the experiments, the electric field gradient was generated by applying an electric field across the two lateral sides of trapezoid (Ba_0.67Sr _0.33)TiO₃ samples. The shear displacement was measured using a laser vibrometer. The converse flexoelectric coefficient f ₁₂₁₂ was found to be 124 ± 14 μ C/m at room temperature. This result was in good agreement with the theoretical prediction of the flexoelectricity of the (Ba, Sr)TiO₃ ceramics.