分極状態の異なる強誘電体PMN-PT単結晶の研磨特性

抄録

The rhombohedral lead magnesium niobate-lead titanate (PMN-PT) single crystal is one of the promising ferroelectric materials having higher ferroelectricity, piezoelectricity and electromechanical coupling coefficient. The single crystals are cut and polished for making various elements, though the polishing characteristic is not well known. PMN-PT relaxor-based ferroelectric single-crystal {001} surfaces in different polarization states were polished on a polyurethane foam polisher with SiO₂ powder comprising particles of 7 nm diameter for obtaining the removal rate and surface roughness. The removal rates depend on the polarity on the surface and applied load. The polished surface roughness depends on the polarity, not on the applied load and the dielectric constant. The polished sample in positively-polarized shows the highest removal rate and lowest surface roughness of 0.324nm Sa. The other hand, that in negatively-polarized shows the lowest removal rate. The polished surface in depolarized has a micro pattern with the appearance of fingerprints owing to the domain structure.