What is the unit cell of diamond?
Diamond is like ZnS (zinc blende). Carbon forming ccp(fcc) and also occupying half of tetrahedral voids. Hence, there are 4 units per unit cell of diamond.
How many atoms are present in diamond?
Crystal structure It is formed of unit cells (see the figure) stacked together. Although there are 18 atoms in the figure, each corner atom is shared by eight unit cells and each atom in the center of a face is shared by two, so there are a total of eight atoms per unit cell.
How many atoms are there in a unit cell?
How many cells are in a unit?
There are three different types of unit cells in the cubic crystal system.
What is the formula for a diamond?
This structure and ultimately the covalent bonding between the Carbons give Diamond its hardness and thermal conductivity. So ultimately the molecular formula of Diamond is C, just like for graphite but the structure is different and so are the properties.
Why is diamond so hard?
The outermost shell of each carbon atom has four electrons. In diamond, these electrons are shared with four other carbon atoms to form very strong chemical bonds resulting in an extremely rigid tetrahedral crystal. It is this simple, tightly-bonded arrangement that makes diamond one of the hardest substances on Earth.
What crystal structure is Diamond?
Diamond is a crystal structure with a face centered cubic Bravais lattice and two atoms in the basis. Carbon, silicon germanium, and α-tin form this crystal structure.
What is the structure of graphite?
Graphite has a giant covalent structure in which: each carbon atom is joined to three other carbon atoms by covalent bonds. the carbon atoms form layers with a hexagonal arrangement of atoms. the layers have weak forces between them.
How many atoms are in primitive unit cell of graphite?
Each unit cell contains a total of four carbon atoms (z=4). One and one sixth (1 1/6) atoms each comes from the first and third layer of the unit cell (top and bottom) and one and two thirds (1 2/3) atoms comes from the second layer (middle layer).
How many allotropic forms of carbon are there?
Variability of carbon Diamond and graphite are two allotropes of carbon: pure forms of the same element that differ in structure.
How many atoms are in a fcc unit cell?
Which of the following unit cell has maximum number of atoms?