0.3truein Figure 10 shows the energy profile of a high boundary: (35). This boundary has relatively large aCSL and a large number of atoms occupying the grain boundary interface (see Figure 3). During GBS process, atoms have many geometric combinations across the interface and each combination corresponds to a specific configuration with energy peak or valley. Such situation results in large number of energy barriers (though some of them have low magnitude) and diversified energy states during GBS, as shown in Figure 10. These energy barriers are the resistance to the GBS process, which make the GBS process very difficult to proceed at 0 K or low temperatures. High temperature provides the thermal vibration to the crystal, atoms can adjust significantly from their equilibrium position to pass the high-energy configurations. Thus at higher temperatures, GBS is expected to play a more important role as a deformation mechanism [2].