“…From this simple approach various improvements have been sought, first accounting for the inter-crystallite piezoelectric coupling, 6 to self-consistent effective medium methods, 7,8 to recent micro-mechanical finite element (FE) approaches. 9,10 However, the inherent weakness of these schemes is the requirement for single crystal data, which is not easily obtainable for many ferroelectrics, especially solid-solution materials such as PZT.…”