Ultra-precision surface grinding of PMN-PT relaxor-based ferroelectric single crystals

Lead magnesium niobate-lead titanate (PMN-PT) single crystals with high piezoelectric coefficients, extremely large piezoelectric strains and very high electromechanical coupling factors are expected to be used in various new sensors and actuators of high performance, instead of lead zirconate titanate (PZT). PMN-PT (0 0 1) planes were ground with various resinoid-bonded diamond wheels in order to obtain thin plates. The features of the ground surfaces change with crystallographic orientation and machining conditions. A surface roughness of 0.44 nm Ra was obtained under adequate grinding conditions. Thin PMN-PT crystals of less than 10 μm thickness were obtained by this grinding process.