Crystal Structure of the High-Pressure Phase of Tellurium

The pressure-induced structural change of tellurium has been studied by powder X-ray diffraction using a diamond-anvil and a cubic-anvil apparatus over the pressure range of 40–100 kbar at room temperature. The diffraction pattern for the high-pressure metallic phase at 45 kbar is interpreted as a monoclinic lattice with lattice constants a =3.104 Å, b =7.513 Å, c =4.760 Å, β=92.71° and V =111.0 Å 3 . The coordinates of the four atoms in a unit cell are given by x 1 =0.25, y 1 =0.23, z 1 =0.48; x 2 =0.48, y 2 =0.0, z 2 =0.02, according to the space group C 2 2 , 2a+2a. This atomic arrangement can be viewed as a layer structure. No further structural change was observed up to 100 kbar.