Figure 1

Diffraction profile from Te-III at 8.5 GPa. The inset shows some of the low-angle reflections (marked with asterisks) whose intensity decreases with increasing pressure, as described in the text.Reuse & Permissions

Figure 2

A diffraction image from a twinned single crystal of Te-III at 7.4 GPa. The main bcm reflections from the two twin components are shown, indexed $(hkl0{)}_1$ and $(hkl0{)}_2$, as well as the indexed satellite reflections. A powder line from the tungsten gasket is marked “G,” while a reflection from one of the diamond anvils is marked “D.”Reuse & Permissions

Figure 3

Rietveld refinement of incommensurate Te-III at 8.5 GPa. The upper and lower tick marks below the profile show the peak positions of the main and first-order satellite reflections, respectively. The reflections shown in Fig. 2 are identified by their indices. The inset shows (i) the pressure dependence of the incommensurate wave vector ($0q0$), and (ii) the maximum atomic displacement, over the range 5 to $\sim 25\mathrm{G}\mathrm{P}\mathrm{a}$. Data from three different samples are distinguished by different symbols.Reuse & Permissions

Figure 4

The compressibility of Te to 36 GPa. The data points below 5 GPa are those from Ref. 10. The inset shows a view down the $a$ axis of four unit cells of Te-III at 8.5 GPa. The six nearest-neighbor contact distances for each atom are shown, and those atoms at the body centers are labeled with “$\frac{1}{2}$.” The modulation wave is indicated by the dotted lines.Reuse & Permissions

Figure 5

Nearest-neighbor contact distances in Te-III at (i) 5.5 GPa and (ii) 23.3 GPa as a function of the phase factor,$t$. The contact distances are from the atom at (000) to the atoms at (a) ($\frac{1}{2}\frac{1}{2}\frac{1}{2}$), (b) ($-\frac{1}{2}-\frac{1}{2}-\frac{1}{2}$), (c) ($\frac{1}{2}-\frac{1}{2}\frac{1}{2}$), (d) ($-\frac{1}{2}\frac{1}{2}-\frac{1}{2}$), and (e) (001) and ($00-1$). In the unmodulated structure, the four contact distances (a)–(d) are the same, as marked by the dashed horizontal lines at 3.104 and 2.965 Å in (i) and (ii), respectively. The grey horizontal band between 2.890 to 2.905 Å shows the limits within which the closest-contact distances lie at all pressures between 5.5 and 23.3 GPa.Reuse & Permissions