Question

How do Schottky defects affect the properties of crystals?

Answer 1

1. Decrease in Density: Due to the missing ions, the mass of the crystal decreases but the volume remains the same, leading to a reduction in density.
2. Increased Electrical Conductivity: The presence of vacancies allows ions to move more easily, enhancing the ionic conductivity of the crystal, especially at higher temperatures.
3. No Change in Stoichiometry: Since an equal number of cations and anions are missing, the chemical composition (stoichiometry) of the crystal remains unchanged.
4. Lattice Becomes Less Stable: The defect introduces disorder in the crystal structure, slightly weakening the lattice stability.
5. Thermal Properties Affected: Schottky defects can affect thermal conductivity and specific heat due to the disruption in the orderly lattice.