Imperfection of Crystal Structure

Classification of imperfections can be describe as below except

• Point defect

• Line defect

• Planar defect

• Bulk defect

• Uniform defect

Point defect are localized disruption in otherwise perfect atomic or ionic arrangements in a crystal structure. These imperfection was introduced by movement of atoms when they gain energy by all causes below EXCEPT?

• Doping

• Heating

• Cooling

• Introduction of impurites

What defect is this?

• interstitial

• vacancy

• substitution

• frenkel defect

This figure show what kind of defects?

• Point defect

• Line defects

• Bulk defect

This defects can be observed by. You can answer more than 1.

• Transmission Electron Micoscope

• Scanning electron microscope

• Xray diffraction

• Atomic Force Microscope

• UV Visible Spectrophotometer

Schottky defect is......

• occur when two oppositely charged ions are missing from an ionic crystal and a cation-anion are created

• occur when a positive cation move into an interstitial site in an ionic crystal and the vacancy-interstitialcy pair is created

Determine the factors that influence the diffusivity level?

• pressure

• temperature

• type of crystal structure

• concentration

• volume

Calculate the energy formation, Qv of a vacancy in copper at 980 degree Celsius, where the equilibrium number of vacancies is 2.1 x 10^25 vacancies per cubic meter. The atomic mass and density for copper at this temperature are 62.8 g/mol and 7.9 g/cm^3, respectively. Given kB = 8.62 x 10^-5 eV/K and Avogadro No, NA= 6.02 x 10^23 atoms/mol.

• 0.780 eV

• 0.885 eV

• 0.123 eV

• 0.655 eV