This document discusses various types of defects in solids, including zero-dimensional point defects like vacancies and Schottky defects, and one-dimensional line defects like edge and screw dislocations. It provides mathematical expressions for calculating the number of vacancy defects based on temperature, total number of atoms, and energy required to create a vacancy. It also describes how Schottky defects arise from missing positive and negative ions in ionic crystals. Finally, it briefly explains edge dislocations as the insertion of an extra half plane of atoms, and screw dislocations as the displacement of atoms to create a jog.

1. GURU NANAK KHALSA
COLLEGE
PHYSICAL CHEMISTRY
BY
SMITA .S. JADHAV
MSC :-1
SEM :-2

2. SOLID STATE CHEMISTRY
 RECAPITULATION :- STRUCTURES AND DEFECTS IN
SOLIDS
TYPES OF DEFECTS AND STOICHIOMETRY
TOPIC:-

3. TYPES OF ZERO DIMENSIONAL (POINT) DEFECTS :-
1)VACANCY DEFECT 2) SCHOTTKY DEFECT
(MATHEMATICAL DERIVATION )
ONE DIMENSIONAL (LINE) DEFECT :- 1) EDGE DISLOCATION
2) SCREW DISLOCATION
CONTENT:-

6.  At the any finite temprature sum of the latice point normally
occupied by metal ions are vacant giving rise to vacancy defect.
 Number of vacancy defects in a given crystalline material depends
upon temprature.
 Total number of metal atoms and average energy required to
create a vacancy.
 If “n” is a number of vacancy and “N” is total number of atoms
or ions and “EV” is average energy required to create a vacancy
then we have,
n= f(T, N,EV)
VACANCY DEFECT:-

8.  Schottky defects arise if same of the latice point in a crystals
are unoccupied the points which are unoccupied are called
lattice vacancies.
 The adjusant of two vacancies one due to misinng a Na+
ions and other due to missing Cl- ions .
 The crystalise as a hole remains natural because missing
number of positive and negative ions are same.
 Schottky defect appears generally ionic crystals in which
positive and negative ions do not differ much in size .
 Because of schottky defect the electrical cunductivity of
SCHOTTKY DEFECT :-

11.  In Edgedislocation , extrahalf plane of atoms is inserted into crystal latice as
shown in fig,
 The crystal plane above and below contains some miss match and
dislocation extends along a lineperpendicular to the plane the crystal is
strain ingricinity of dislocation inorder to occumated extra.
SCREW DISLOCATION :-
o Formation of screw dislocation canbe visualisedby cutting a ruber bulb
parallel to its axisand then to shift one end so that the jog is created such
displacement of atom is called as screw dislocation.
 EDGE DISLOCATION:-

13.  SOLID STATE 2nd EDITION, LESLEY SMART AND ELAINE
MOORE , PAGE NO:-159,160, 166-203
ANTHONY R . WEST , JOHN WILEY AND SONS , PAGE NO:-
320-355
Dr K . YADAV , PAGE NO:- 79-99
Dr . HARISH CHANDER ALFA PUBLICATIONS , (NEW
DELHI) – 110002 , PAGE NO:-15-21
M.G.ARORA , PAGE NO:- 115-121
REFERENCES:-