Fig. 7.

Typical microstructures for Eu_0.2Yb_0.2Ca_0.6Mg₂Bi₂. (A) Medium-magnification TEM image showing mesoscale grains with black precipitates. (B) EDS spectra for matrix (Left) and precipitate (Right) with elemental composition data. (C) HRTEM image of grain boundary showing good crystallization. (Inset) The selected area electron diffraction pattern. (D) Semicoherent strain by misfit dislocation around the grain boundary. (E) Incoherent interaction near the grain boundary. (F) Coherent strain inside the grain. G–I are schematic diagrams illustrating three possible types of semicoherent, incoherent, and coherent interactions, respectively, with inset magnification of one segment corresponding to D–F, respectively (larger yellow circles represent dopants).