Figure 4

SEM micrographs show the variation of the morphology of the dendritic structures above T_P after experiencing successive polishing: (a–d) are views of the corresponding structures shown in Fig. 2(a–d) after a polishing of 50 μm; (e–h) are views of the corresponding structures shown in Fig. 3(a–d) after a polishing of 50 μm.