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#### Abstract

Structures of Metals and Ceramics

**Goals**

- Define basic terms and give examples of each:
- Lattice
- Basis Atoms (Decorations or Motifs)
- Crystal Structure
- Unit Cell
- Coordination Numbers

- Describe hard-sphere packing and identify cell symmetry
- Crystals density: the mass per volume (e.g. g/cm
^{3}) - Linear Density: the number of atoms per unit length (e.g. cm
^{-1}) - Planar Densities: the number of atoms per unit area (e.g. cm
^{-2})

**Learning Objective**

- Know and utilize definitions to describe structure and defects in various solid phases (crystal structures)
- Compute densities for close-packed structures
- Identify Symmetry of Cells
- Specify directions and planes for crystals and be able to relate to characterization experiments

**Content**

- ENERGY AND PACKING
- Atomic PACKING
- Crystalline Solids: Unit Cells
- Unit Cells and Unit Cell Vectors
- Possible Crystal Classes
- Unit Cells Types
- The 14 Bravais Lattices!
- Counting Number of Atoms Per Unit Cell
- UNIT CELL - 3D Lattices
- Coordination Number of a Given Atom
- Unit Cells and Volume Packing
- Atomic Packing Fraction for FCC
- Basic Geometry for FCC
- Atomic Packing Fraction for FCC
- Summary APF for BCC
- FCC Stacking
- Comparing the FCC and HCP Planes Stacking
- Packing Densities in Crystals: Lines Planes and Volumes
- Linear Packing Density in FCC
- Planar Packing Density in FCC
- Theoretical Density
- Characteristics of Selected Elements at 20 C
- DENSITIES OF MATERIAL CLASSES
- SUMMARY

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