Structure of Crystalline Solids - Chapter 4

Question 1

Coordination number of BCC?

Answer 1

8

Question 2

Unit number of atoms in BCC?

Answer 2

2

Question 3

Unit number of atoms formula?

Answer 3

N = Ni + Nf/2 + Nc/8

Question 4

Atomic packing factor of BCC?

Answer 4

0.68

Question 5

FCC:

Answer 5

Face Centered Cubic Structure

Atoms located at each of the corners and the centers of all the cube faces.

Question 6

Three Main Crystal structures:

Answer 6

FCC - Face-centered structure
BCC - Body-centered structure
HCP -

Question 7

FCC cube length a?

Answer 7

a = 2R* Sqrt[2]

Question 8

FCC coordination number?

Answer 8

12

Question 9

Unit number of atoms in FCC?

Answer 9

4

Question 10

Atomic Packing Factor of FCC?

Answer 10

0.74

Question 11

Atomic Packing Factor(APF)?

Answer 11

The APF is the sum of the sphere volumes of all atoms within a unit cell divided by the unit cell volume.

APF = Volume of atoms in a unit cell/total unite cell volume

Question 12

BCC:

Answer 12

Body centered cubic structure:

Atoms located at all eight corners and a single atom at the cubic center.

Question 13

BCC unit cell length a?

Answer 13

a = 4R/Sqrt[3]

Question 14

HCP:

Answer 14

Hexagonal close-packed:

The top and bottom faces of the unit cell consists of six atoms that form regular hexagons and surround a single atom in the center. Another plane that provides three additional atoms to the unit cell is situated between the top and bottom planes.

Question 15

Number of atoms per unit cell for HCP:

Answer 15

N = Ni + Nf/2 + Nc/6

Question 16

Unit number of atoms in HCP:

Answer 16

N = 3 + 2/2 + 12/6 = 6

Question 17

Coordination number of HCP?

Answer 17

12

Question 18

Atomic packing factor of HCP?

Answer 18

0.74