Experimental determination of flexoelectric coefficients in SrTiO3, KTaO3, TiO2, and YAlO3 single crystals

We report experimental values for the flexoelectric responses of SrTiO3, KTaO3, TiO2, and YAlO3 single crystals using a three-point bending approach. We find all samples possess a linear flexoelectric response with effective short-circuit flexoelectric coefficients similar to vertical bar 1-10 vertical bar nC/m. Flexocoupling voltages computed from these measured effective flexoelectric coefficients are found to significantly vary across the investigated materials and refute the previous suggestions that they should be similar to vertical bar 1-10 vertical bar V. Importantly, we find that low dielectric constant materials can have large flexocoupling voltages exceeding nominal expectations.