Crystallographic texture optimisation in polycrystalline ferroelectric films for Random Access Memory applications

The present paper analyses the effect of crystallographic texture on the electromechanical interactions of polycrystalline PZT films. These interactions are responsible for inducing local enhancements of the remnant polarisation. Built-in stresses and electric fields are responsible for asymmetries in the local shape of the hysteretic loop that are as large as 25% in the coercive field and 10% in the out-of-plane remnant polarisation. Simulations show two types of 180° domain walls are favoured: stress-free and mechanically tensile polarisation interfaces. For [001] fibre textured grains a texture of 37 MRDs (r = 0.3) will maximise the performance of individual memory units.