Grain boundary grooving by surface diffusion in SrTiO3 bicrystal

High-purity SrTiO3 bicrystal sample (the angle between two [001] directions is 24 degrees) was used in the present experiment to develop a thermal gra in boundary groove along the bicrystal grain boundary at different temperat ures (1150-1400 degrees C) and times (15-6720 min) in air. An atomic force microscope (AFM) was used to observe the surface morphological change in th e annealed bicrystal sample in order to measure the width W and depth h of the developed grain boundary groove. It was found that the log W-log t (at 1150-1400 degrees C) and the log h-log t (at 1400 degrees C) relationships are approximately linear, having slopes of approximately 1/4. Using Mullins ' formulas, the surface diffusion coefficients of SrTiO3 at different tempe ratures were calculated. Finally, the surface diffusion coefficient determi ned in the present experiment appears to correspond to the titanium atom, w hich has the lowest diffusivity in SrTiO3..