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Crystallographic Positions Body Centered Cubic Structure (BCC) Face Centered Cubic Structure (FCC) Where Are The Atoms Located ? x y z x y z

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Page 1: Crystal Lo Graphic Planes

Crystallographic PositionsBody Centered Cubic Structure

(BCC)

Face Centered Cubic Structure

(FCC)

Where Are The Atoms Located ?x

y

z

x

y

z

Page 2: Crystal Lo Graphic Planes

Crystallographic Positions

x

y

z

100

011001

½ ½ ½

Page 3: Crystal Lo Graphic Planes

Crystallographic DirectionsBody Centered Cubic Structure

(BCC)

Face Centered Cubic Structure

(FCC)

y

z

x

y

z

In Which Direction Are The Atoms Touching?x

Page 4: Crystal Lo Graphic Planes

Crystallographic Directions, [u v w]

x

y

z

[101]

[010]

[111]

Page 5: Crystal Lo Graphic Planes

Crystallographic Directions, [u v w]

x

y

z

[010]

[121]

Page 6: Crystal Lo Graphic Planes

Crystallographic Directions, [u v w]

x

y

z

[101]

[011]

Page 7: Crystal Lo Graphic Planes

Family of Crystallographic Directions, <u v w>

x

y

z

[101]or

[101]

<110>

]110[],101[],110[],011[]101[],110[],011[],101[]011[],011[],101[],110[

[110]or

[110]

Page 8: Crystal Lo Graphic Planes

Crystallographic DirectionsBody Centered Cubic Structure

(BCC)

Face Centered Cubic Structure

(FCC)

y

z

x

y

z

In Which Direction Are The Atoms Touching?[111] for BCC and [110] for FCC

x

Page 9: Crystal Lo Graphic Planes

Crystallographic Directions: Linear Density (LD)BCC: Atoms Touch Along the

[111] Direction

y

z

x

[111]

[100]

[110]

4ra3 o =

[111] DirectionClosest Packed Direction

1a3

4rLDo==

[110] Direction

612.0 3

42

2a2

2rLDo

=

==rr

[100] Direction

866.0 3

42

a2rLD

o

=

==rr

Page 10: Crystal Lo Graphic Planes

Crystallographic Directions: Linear Density (LD)FCC: Atoms Touch Along the

[110] Direction 4ra2 o =

[111] Direction

1a3

4rLDo==

[110] Direction: Closest Packed Dir.

[100] Direction

707.0 2

42

a2rLD

o

=

==rr

y

z

x

[111]

[100][110]

408.0

243

2a3

2rLDo

=

==rr

Page 11: Crystal Lo Graphic Planes

Crystallographic PlanesBody Centered Cubic Structure

(BCC)

Face Centered Cubic Structure

(FCC)

y

z

x

y

z

In Which Plane Are The Atoms Closest Packed?x

Page 12: Crystal Lo Graphic Planes

Crystallographic Planes: Miller Indices (hkl)

x

y

z

x

y

z

Given a Geometric Plane

If Necessary, Move the Origin so that All Intercepts are Found within the Unit Cell

Determined the Intercepts

Take Reciprocal

Change to Smallest Integer

(hkl)

Page 13: Crystal Lo Graphic Planes

Crystallographic Planes: Miller Indices (hkl)

x

y

z

x

y

z

(111)

(121) x

y

z

x

y

z

(010)

(020)

Page 14: Crystal Lo Graphic Planes

Crystallographic Planes: Miller Indices (hkl)

x

y

z

x

y

z

(210)

x

y

z

x

y

z

(021)

x’

z’

x’

y’

Page 15: Crystal Lo Graphic Planes

Crystallographic Planes: Miller Indices (hkl)

x

y

z

x

y

z

Given a Miller Indices (hkl)

If Necessary, Move the Origin. Move in the Positive Direction for a Negative Indices

Take Reciprocal

Indicate the Intercepts

Connect the Dots

(121)

Page 16: Crystal Lo Graphic Planes

Crystallographic Planes: Miller Indices (hkl)

x

y

z

x

y

z

Given a Miller Indices (hkl)

If Necessary, Move the Origin. Move in the Positive Direction for a Negative Indices

Take Reciprocal

Indicate the Intercepts

Connect the Dots

(211)z’

y’

Page 17: Crystal Lo Graphic Planes

Family of Crystallographic Planes

x

y

z{111}

)111(),111(),111(),111()111(),111(),111(),111(

(111)

{111}

Page 18: Crystal Lo Graphic Planes

x

y

z

Series of Crystallographic Planes

x

y

z

(121)

(010)

Page 19: Crystal Lo Graphic Planes

Crystallographic PlanesBody Centered Cubic Structure

(BCC)

Face Centered Cubic Structure

(FCC)

y

z

x

y

z

In Which Plane Are The Atoms Closest Packed?{111} for BCC and {100} for FCC

x

Page 20: Crystal Lo Graphic Planes

Crystallographic Planes: Planar Density (PD)

BCC

y

z

x

BCC: Atoms Touch Along the <111> Directionsand Are Closest Packed in {110} Planes

4ra3 o =

0.589 3

4rπr

aπrPD 2

2

2o

2

=

==(100) Plane

(110) Plane

0.834 3

4r2

r2πa2r2πPD 2

2

2o

2

=

⋅=

⋅=

Closest Packed PD

Page 21: Crystal Lo Graphic Planes

Crystallographic Planes: Planar Density (PD)FCC: Atoms Touch Along the <110> Directions

and Are Closest Packed in {111} Planes

4ra2 o =

0.785 2

4rr2π

ar2πPD 2

2

2o

2

=

⋅=

⋅=

(100) Plane

(110) Plane

0.555 2

4r2

r2πa2r2πPD 2

2

2o

2

=

⋅=

⋅=

x

y

z

Page 22: Crystal Lo Graphic Planes

Crystallographic Planes: Planar Density (PD)FCC: Atoms Touch Along the <110> Directions

and Are Closest Packed in {111} Planes

4ra2 o =

901.0

232

21

6rπ3

2rπ3

PD

22

=

⋅+⋅⋅=

oo aa

(111) Plane

Closest Packed PDx

y

z