1. © Oxford Instruments Analytical Limited 2001 MODULE 2 - Introduction to Basic Crystallography Bravais Lattices Crystal system Miller Indices Crystallographic Direction Zone Axis Zones in the EBSP Indexing Euler Angle Euler Space - ODF's Orientation Matrix Ideal Orientation Nomenclature Misorientation Crystal Forms Describing Planes and Directions Describing Orientations Determining the Orientation Describing Misorientations

2. © Oxford Instruments Analytical Limited 2001 Introduction to Basic Crystallography - Bravais Lattices There are 14 Bravais Lattices: Note: Body Centered Cubic (BCC) and Face Centred Cubic (FCC) forms From these 7 crystal systems are derived

3. © Oxford Instruments Analytical Limited 2001 Introduction to Basic Crystallography - Crystal System These terms describe the geometry of the unit cell - the structure that is repeated throughout the crystal. There are seven Crystal systems: 1. Cubic 2. Hexagonal 3. Trigonal 4. Tetragonal 5. Orthorhombic 6. Monoclinic 7. Triclinic The lengths of the sides of the unit cell are shown below as a, b and c. The corresponding angles are shown as alpha, beta and gamma.

4. © Oxford Instruments Analytical Limited 2001 Introduction to Basic Crystallography - Miller Indices For a cubic example, Miller indices can be derived to describe a plane Consider a cubic unit cell with sides a, b, c, with an origin as shown

5. © Oxford Instruments Analytical Limited 2001 Introduction to Basic Crystallography - Crystallographic Direction A crystallographic direction describes the intersection of specific faces or lattice planes Miller Indices can be used to describe directions For a cubic material the plane and the normal to the plane have the same indices

6. © Oxford Instruments Analytical Limited 2001 Introduction to Basic Crystallography - Zone Axis ‘Zone’: faces or planes in a crystal with parallel intersections. Zone Axis: The common direction of the intersections