Atomic Structure and Properties of the (310) Symmetrical Tilt Grain Boundary (STGB) in SrTiO_3 Part II: Comparison with Experimental Studies

摘要

The atomistic simulation results presented in Part I for SrTiO_3 (310) symmetrical tilt grain boundary (STGB, the so-called Σ = 5 GB with 36.8° symmetrical misorientation about [001]) are analyzed in the context of available experimental studies. In particular, atomic imaging studies of SrTiO_3 GBs via high resolution TEM and incoherent Z-contrast STEM imaging; and determination of oxygen positions by combining electron energy loss spectroscopy (EELS) and bond-valence-sum rules, are compared with simulation results. The atomistic simulation data on the GB energies are compared with relative experimental estimates obtained via a novel approach of faceting of focused ion beam (FIB) induced microvoids. While there are considerable differences in details of simulation and experimental results, some basic trends seem to emerge about the core structural framework of GBs in SrTiO_3. The paper highlights the limitations of both, experimental and simulation techniques, and argues in favor of synergistic use of diverse experimental and simulation approach to determine the atomic structure and properties of GBs.