31/10/2019

1

26 27

28 29

26 27

28 29

31/10/2019

2

30 31

32 33

30 31

32 33

31/10/2019

3

34 35

36 37

34 35

36 37

31/10/2019

4

38 39

40 41

38 39

40 41

31/10/2019

5

42 43

44 45

BURGERS VECTOR

The magnitude and the direction of the displacement are defined by a vector, called the Burgers Vector.

In figure (a), starting from the point P, we go up by 6 steps, then move towards right by 5 steps, move down by 6 steps and finally move towards left by 5 steps to reach the starting point P. the Burgers circuit gets closed.

When the same operation is performed on the defect crystal (figure (b)) we end up at Q instead of the starting point.

42 43

44 45

31/10/2019

6

46

BURGERS VECTOR

So, we have to move an extra step to return to P, in order to close the Burgers circuit.

The magnitude and the direction of the step defines the Burgers Vector (BV).

BV = = b

The Burgers Vector is perpendicular to the edge dislocation line.QP

47

48 49

46 47

48 49

31/10/2019

7

50 51

52 53

50 51

52 53

31/10/2019

8

54 55

56 57

54 55

56 57

31/10/2019

9

58 59

60 61

58 59

60 61

31/10/2019

10

62

62