Search results
Results from the WOW.Com Content Network
The atomic packing factor of the diamond cubic structure (the proportion of space that would be filled by spheres that are centered on the vertices of the structure and are as large as possible without overlapping) is , [3] significantly smaller (indicating a less dense structure) than the packing factors for the face-centered and body-centered ...
The diamond cubic crystal structure occurs for example diamond , tin, and most semiconductors. There are 8 atoms in the cubic unit cell. We can consider the structure as a simple cubic with a basis of 8 atoms, at positions
BCC structure. The primitive unit cell for the body-centered cubic crystal structure contains several fractions taken from nine atoms (if the particles in the crystal are atoms): one on each corner of the cube and one atom in the center. Because the volume of each of the eight corner atoms is shared between eight adjacent cells, each BCC cell ...
Altogether, the arrangement of atoms in zincblende structure is the same as diamond cubic structure, but with alternating types of atoms at the different lattice sites. The structure can also be described as an FCC lattice of zinc with sulfur atoms occupying half of the tetrahedral voids or vice versa. [6]
Below 13.2 °C, tin exists in the gray form, which has a diamond cubic crystal structure, similar to diamond, silicon or germanium. Gray tin has no metallic properties at all, is a dull gray powdery material, and has few uses, other than a few specialized semiconductor applications. [ 24 ]
Because it is cubic in structure, diamond is also isotropic. Its high dispersion of 0.044 (variation of refractive index across the visible spectrum) manifests in the perceptible fire of cut diamonds. This fire—flashes of prismatic colors seen in transparent stones—is perhaps diamond's most important optical property from a jewelry perspective.
The diamond crystal structure belongs to the face-centered cubic lattice, with a repeated two-atom pattern. In crystallography , a crystal system is a set of point groups (a group of geometric symmetries with at least one fixed point).
2×2×2 unit cells of a diamond cubic lattice. In three-dimensional space there are 14 Bravais lattices. These are obtained by combining one of the seven lattice systems with one of the centering types. The centering types identify the locations of the lattice points in the unit cell as follows: