Analysis of phase distributions in the Li2O-Nb2O5-TiO2 system by piezoresponse imaging

The M-phase solid solutions Li1+xNb1-x-3yTix+4yO3) (0.1 less than or equal to x less than or equal to 0.3, 0 less than or equal to y less than or equa l to 0.175) in the Li2O-Nb2O5-TiO2 system have promising microwave dielectr ic properties. However, these compounds can contain small quantities of fer roelectric impurities that affect the polarization response of the material . Due to their low concentration and their chemical similarity to the host material, the impurities cannot be detected by x-ray diffraction or local e lemental analysis. Scanning surface potential microscopy and piezoresponse imaging were used to analyze phase compositions in this system. Piezorespon se imaging demonstrated the presence of thin (<200-300 nm) ferroelectric la yers on the grain boundaries oriented along the c-axis of the M-phase. Diff erences between the surface potential and the piezoresponse of ferroelectri c multicomponent systems are discussed.