Exam 2 material science

hnbh

What all do a solid solution depend on

• Atomic size: Similar atomic radii favor dissolving.

• Crystal structure: The same crystal structure favors dissolving.

• Electronegativity: Similar values favor dissolving.

• Valence: The same valence favors dissolving.

Types of imperfections

Point defects (0-D):

• Vacancy: An atom is missing from its normal position.

• Interstitial: An extra atom fitting in a space between normal atomic positions.

• Substitutional: An atom of a different element replaces a host atom.

Line defects (1-D):

• Dislocations: Disruptions in the atomic arrangement that extend along a line.

Area defects (2-D):

• Grain boundaries: Surfaces where grains with different crystal orientations meet.

Volume defects (3-D):

• Voids: Empty regions within the material.

• Inclusions: Regions of foreign material within the material.

Two common point defects in metal or elemental semiconductor structures are….

the vacancy(0-d defect) and the interstitial(0-d defect)

Two common point defect structures in compound structures are….

the Schottky defect and the Frenkel defect

Screw dislocation

-spiral within the latice structure wrapped around an imperfection line

Mixed dislocation

his dislocation has both edge and screw character
with a single Burgers vector consistent with the pure edge and pure screw regions