Figure 3
(a) Example of an unrolled radial diffraction image for a sample of h.c.p.-Co at 42.6 GPa in the diamond anvil cell. The image shows the diffraction as a function of the Bragg angle 2θ and the azimuth angle on the image plate δ (Fig. 2). The sinusoidal variations in positions of the diffraction lines are due to elastic deformation and stress in the sample; intensity differences along lines indicate preferred orientation caused by plastic deformation. The compression direction is indicated by the dark arrows. (b) Average stress (thick solid lines) and local stress components in single grains (thin dashed lines) versus pressure for a Co polycrystal plastically deformed in the diamond anvil cell. Results of EPSC calculations optimized to lattice strains measured experimentally (Merkel et al., 2009). |