Explain Schottky defect.

Schottky defect is-

Explain Schottky and Frenkel defects.

Define Frenkel and Schottky defects with examples.

Statement : Schottky defect is generally shown by the compounds with high co - ordination no. Explanation : Equal no. of cations and anions are missing from the lattice sites in Schottky defect.

An ionic crystal with Schottky defects has-

What is Schottky defect ? Find out the packing effciency in a simple cubic lattice ?

Which of the following point defect are shown by AgBr crystals: (i) Schottky defect (ii) Frenkel defect (iii) Metal excess defect (iv) Metal deficiency defect-

Give reasons : (i) In stoichiometric dfects. NaCl exhibits Schottky defect and not Frenkel defect. (iii) Ferrimagnetic substances show better magnetism than antiferromagnetic substances.

(a) Calculate the number of unit cell in 8.1g of aluminium if it crystallises in a fcc structure. (Atomic mass of Al = 27 g*mol^(-1) ) (b) Give reasons: (i) In stoichiometric defects, NaCl exhibits Schottky defect and not Frenkel defect. (ii) Silicon on doping with Phosphorous forms n-type semiconductor. (iii) Ferrimagnetic substances show better magnetism than anti-ferromagnetic substances.

Silver crystallises in face-centred cubic lattice. If edge length of the unit cell is 4.07xx10^(-8)cm and density of silver is 10.48g*cm^(-3) , determine the relative atomic mass of silver. or, (i) What is Schottky defect? (ii) Find out packing efficiency in a simple cubic lattice.