MSE Notes Exam 1

Electron Configurations

Describe the arrangement of electrons in an atom's energy levels and subshells.

Crystalline Solids

Solids that exhibit long-range periodic order over large atomic distances.

Amorphous Solids

Solids that lack long-range order.

Coordination Number

The count of nearest-neighbor atoms touching a central atom.

Atomic Packing Factor (APF)

The volume of atoms in a unit cell divided by the total unit cell volume.

Simple Cubic (SC)

A type of metallic unit cell with the lowest APF of 0.52 and a coordination number of 6.

Body-Centered Cubic (BCC)

A type of metallic unit cell with an APF of 0.68 and coordination number of 8.

Face-Centered Cubic (FCC)

A unit cell with the highest APF of 0.74 and coordination number of 12.

Hexagonal Close-Packed (HCP)

Another unit cell type with an APF of 0.74 and coordination number of 12.

Stacking Sequence for FCC

The close-packed pattern follows an ABCABC… arrangement.

Stacking Sequence for HCP

The close-packed pattern follows an ABAB… arrangement.

Percent Ionic Character Equation

Quantifies the degree of ionic character in a chemical bond based on electronegativity difference.

Interatomic Potential Energy Curve

Graph showing potential energy versus atomic radius distance, revealing material bonding and properties.

Crystallographic Directions

Specified using Miller indices, denoted as [hkl].

Crystallographic Planes

Specified using Miller indices, denoted as (hkl).

Linear Density (LD)

Defined as the number of atoms along a direction vector divided by the length of that vector.

Planar Density (PD)

Defined as the number of atoms on a crystallographic plane divided by the area of that plane.

Point Defects

Zero-dimensional structural defects in crystalline materials, including vacancies and self-interstitials.

Vacancy Equilibrium Concentration

Depends on absolute temperature and follows the Arrhenius relationship.

Linear Defects

One-dimensional dislocations that facilitate plastic deformation.

Hume-Rothery Rules

Governs solid solubility of solute atoms in a solvent matrix based on four criteria.

Fick's First Law

Describes mass transfer under steady-state conditions, expressed as J = -D (dC/dx).

Fick's Second Law

Describes non-steady-state diffusion, expressed as ∂C/∂t = D ∂²C/∂x².

Arrhenius Equation for Diffusion Coefficient (D)

Describes how D increases exponentially with temperature, expressed as D = D₀ e^(-Q_d/(RT)).