Electron backscatter diffraction analysis of Pb(Mg_1/3Nb_2/3)O_3-35mol percent PbTiO_3 single crystals grown by seeded polycrystal conversion

摘要

Electron backscatter diffraction (EBSD) has been applied to characterize Pb(Mg_1/3Nb_2/3)O_3 -35 mol percent PbTiO_3 single crystals grown by the seeded polycrystal conversion method. Macroscopically triangular crystal growth fronts were shown to each be associated with discrete crystals that originated from slightly misoriented segments of an initially cracked single-crystal seed plate. Various types of crystal imperfections, including voids, second-phase regions, and polycrystalline matrix grains trapped within the grown region, were readily identified and distinguished from one another using EBSD. Further, it was shown that trapped matrix grains in the grown region had consistently small misorientations with respect to the grown single crystal and this may be qualitatively explained by a simple boundary energetics argument. The significance of the trapped grains is discussed.