Imperfection of solid

When Cat-ion and Anion regular arrange in crystal than some ion dislocate their position or missing their crystal that indicate imperfection of solid.

             Some ion (Cat-ion or anion) arrange at 0 degree Kelvin which is called ideal solid.

·         There are different type of defect

.    1. Impurity defect :-  Impurity defects are foreign atoms that replace some of the atoms making up the solid or that squeeze into the interstices; they are important in the electrical behavior of semiconductors, which are materials used in computer chips and other electronic devices.

    2.  Stoichiometric defect  :-    The compounds in which the number of positive and negative ions are exactly in the ratios indicated by their chemical formulae are called stoichiometric compounds. The defects do not disturb the stoichiometry (the ratio of numbers of positive and negative ions) are called stoichiometric defects.

    Schottky defect:-  when  atom or ion regular arrange in crystal then same number of cation and anion missing their crystal which is called schottky defect.

   Density decreases in schottky defect. AgBr source frenkel defect and schottky defect.

Frenkel defect:-  When atom or ion arrange in crystal then one cation dislocated their position but present in crystal that is called frenkel defect.

    Vacancy defect:- In this defect when atom or ion regular arrange in crystal then sometime iron are vacant their position and electron occupy their space which is called vacancy defect.

·         Vacancy defect develop in presence of heat.

·         In vacancy defect F-center are develop.

      Interstitial defect:-  Interstitials defects are a variety of crystallographic defects where atoms assume a normally unoccupied site in the crystal structure. In interstitial defects, two or more atoms may share one lattice site, thereby increasing its total energy.

    3.     Non-stoichiometry defect:-  

     Metal Excess defect:- when metal and nonmetal regular arrange in crystal then number of metal is higher than number of non-metal that is fold metal excess defect.

                                             

    Metal Deficiency defect:- Metal and nonmetal regular range in crystal then number of metal is lower than number of non-metal, which is called metal deficiency defect.

Packing efficiency and Void

Packing efficiency  

The total percentage of space occupy by atom molecule or ion in unit cell that is called packing efficiency

Void or space or holes

              Empty or vacant space present between spheres of a unit cell , is called void. When particles are closed packed resulting in either CPP or HCP structure, two types of void generated.

Tetrahedral void :- Tetrahedral voids are holes or voids surrounded by four spheres present at the corner of a tetrahedron. Co-ordination number of a tetrahedral void is 4.

Octahedral void:- Octahedral void are holes or voids surrounded by six spheres located on a regular tetrahedron. Co-ordination number of a tetrahedral void is 6. 

Close packed Structure

Co-ordination number: - The total number of atom which is directly attached with one atom that is called co-ordination number.

	Co-ordination number
1-Dimention	2
2-Dimention	AAA –type 4, ABAB-type 6
S.C.C.	6
B.C.C.	12
F.C.C.	8

Close packed Structure 

The term "closest packed structures" refers to the most tightly packed or space-efficient composition of crystal structures (lattices). Imagine an atom in a crystal lattice as a sphere. ... These arrangements are called closest packed structures. The packing of spheres can describe the solid structures of crystals.

Number of atom ,Atomic Radius and Density of Unit Cell

Number of atom in SCC , BCC , and FCC

Calculation of Atomic Radius

Density of unit cell

Na = 6.023 X 10²³

magnetic properties of solid

Solid substance shows magnetic properties.

There are different type-

1. Paramagnetic: - a solid substance which is weakly attached from magnetic field that is called paramagnetic. This property of substance is called paramagnetic properties.

Magnetic value always greater than 0 of paramagnetic substance.

Ex- sulfur, Phosphorus and nitrogen, etc.

2. Diamagnetic: - sorry substance which is not attached from magnetic field that is called diamagnetic. This property of substance is called Diamagnetic properties.

Magnetic value always equal to zero of diamagnetic substances.

Ex- Helium, Neon, Argon, Krypton, etc.

3. Ferromagnetic: - a solid substance which is strongly attached from magnetic field that is called ferromagnetic. This property of substance is called ferromagnetic properties.

In Ferromagnetic substance, maximum number of unpaired electron present.

Ex- chromium iron Cobalt nickel etc.

4. Antiferromagnetic: - a solid substance in which electron regular arrange in same spin and opposite spin that is called antiferromagnetic. This property of substance is called antiferromagnetic property.

Ex- FeO , MnO2, MnO, etc.

*Ferromagnetism: - A solid substance in which electron irregular arrange in same and opposite spin that is called ferromagnetism.

*Dialectical properties:- those solid substance in which electric current does not flow that is called dielectric substance. This property of substance is called dielectric property.

Dielectric properties are of two types-

1 pyroelectric properties: - a solid substance in which electric current slightly flow after heating that is called pyro electrical properties.

2 Piezoelectric properties: - substance image electric current flow after giving mechanical force, that is called electrical properties.

#radius ratio: - the ratio of radius of cation and radius of anion is called radius ratio.

Radius ratio= radius of cation/radius of anion

electric properties of solid

Solid substance a shoes electrical properties which is three types

·         Conductor

·         Insulator

·         Semiconductor

Conductor - A Solid substance in which electric current easily flow that is called conductor. Conductivity range of conductor between 10 to the power 4 into 10 to the power 7 per ohm per meter.

Insulator-A solid substance in which electric current does not flow that is called insulator. Conductivity range of insulator is between 10 to the power -20 10 to the power -10.

Semiconductor- A solid substance which is insulator on ground state but in presence of heat it works as conductor that is called semiconductor. Conductivity royal range of semiconductor is between 10 to the power minus 6 to 10 to the power 4 per ohm per meter.

Doping: - the process in which semiconductor convert into conductor after mixing impurities that is called doping. 

Ex- five A group element in silicon, third A group element doped in silicon, etc.

1.     N type semiconductor

                  As we know that silicon is a semiconductor which have four valence electron. When v A group element (P) doped with silicon for conversion of conductor then for electron of phosphorus bonded with four silicon and one unpaired electron present on phosphorus that is why, it is called electron rich impurities or n type semiconductor.

2.     P type semiconductor

As we know that silicon is a semiconductor which have four valence electron. When 3rd A  group element (Al) doped with silicon for conversion of conductor then three electron of Aluminum  on fondant with 3 silicon and one unpaired electron present on silicon that is why it is called electron poor impurities or p-type semiconductor.