Clausius Masotti Equation, Piezo-Electric, Pyro-Electric & Ferro-Electric Materials, Dielectric Loss and Loss Tangent.

1. DEPARTMENT OF ELECTRICAL ENGINEERING
Subject Name:- Electrical Engineering Material [EEM]
Topic Name :-Clausius Mossotti Equation,
Piezo-Electric,
Pyro-Electric & Ferro-Electric Materials,
Dielectric Loss and Loss Tangent.
Group No. :- 9

2. Topics:-
 Clausius Mossotti Equation.
 Piezo-Electric.
 Pyro-Electric & Ferro-Electric
Materials.
 Dielectric loss and loss tangent.

3.  Clausius Mossotti Equation
Ottaviano-Fabrizio Mossotti (18 April 1791 – 20 March 1863)
was an Italian physicist who was exiled from Italy for
his liberal ideas. During the First Italian War of Independence he
led a "battalion of students," part of a delegation from the Grand
Duchy of Tuscany. He later taught astronomy and physics at
the University of Buenos Aires. His studies on dielectrics led to
important results: the Clausius Mossotti formula is partly named
after him.
Rudolf Julius Emanuel Clausius (2 January 1822 – 24 August
1888) was a German physicist and mathematician and is considered
one of the central founding fathers of the science
of thermodynamics

4.  Clausius Mossotti Equation
 This equation is derived based on certain
assumptions, such as the non-interacting nature
of the molecules and the isotropy of the
material. It is particularly useful in
understanding the behavior of materials in the
presence of electric fields, such as the response
of dielectric materials to external electric fields.
 The Clausius-Mossotti equation is often applied
in the context of understanding the optical
properties of materials, including their refractive
index and how it changes with the frequency of
incident light.

5.  Clausius Mossotti Equation

6.  Clausius Mossotti Equation

7.  Piezo-Electric
 The materials which convert mechanical strain applied to them
into electrostatic charges on the face of crystal are called
piezoelectric materials and its phenomenon is called as
piezoelectricity.
 Piezoelectricity provides mechanism for converting electrical
energy into mechanical stress or strain and vice versa.
 Piezoelectric effect is nothing but production of electricity by
applying pressure.
 It is found that all piezoelectric materials are ferroelectric
materials too.
 Piezoelectricity occurs in materials only when the lattice has no
centre of symmetry.
 There are two types of effects of piezoelectricity
1) Inverse piezoelectric effect (electrostriction)
2) Direct piezoelectric effect
Jacques Curie (29 October 1855 – 19
February 1941) was a
French physicist and professor
of mineralogy at the University of
Montpellier Along with his younger
brother, Pierre Curie, he
studied pyroelectricity in the 1880s,
leading to their discovery of some of the
mechanisms behind piezoelectricity
He is buried in the Saint - Lazare
cemetery in Montpellier.

8.  Inverse Piezoelectric Effect

9.  Inverse Piezoelectric Effect
 When an electric field is applied to dielectric, it becomes polarized due to which
nuclei and electrons taken new geometric position.
 Due to this mechanical dimension of material can be altered. This phenomenon
of mechanical deformation of dielectric caused by external electric field is called
inverse piezoelectric effect.
 If alternating voltage is applied between the two opposite faces of the crystal, it
vibrates with the frequency of the field.

10.  Direct PiezoelectricEffect

11.  Direct PiezoelectricEffect
 The production of electric polarization by application of mechanical stresses is
known as direct piezoelectric effect.
 If mechanical pressure on crystal is altered, and a varying voltage which is
proportional to mechanical pressure is produced by the crystal.
 The voltage generated can be as small as fraction of voltage or can be thousands
of volts depending upon the piezoelectric material and pressure applied.
 Ammonium nitrate, Quartz, Rochelle salt, Barium titanate (BaTiO3) exhibit
piezoelectric properties.

12.  Applications of PiezoelectricMaterials
 For conversion of mechanical stress into electric signal such as transducer,
oscillators, multivibrators, strain gauges.
 Piezoelectric semiconductors like CdS, ZnS, ZnO are used to transform
electromagnetic vibrations into audio signals at very high frequencies (amplifiers
of ultrasonic waves).
 Piezoelectric materials serves as a source of ultrasonic waves. At sea, they can be
used to measure depth, the distance to shore, the position of ice berg submarines.
 Inverse piezoelectric effect is used in Quartz watches which keep accurate time.

13.  Pyro-Electric Materials
 All pyro-electric materials are
piezoelectric.
 Thus, the heat absorbed by the pyroelectric
crystal, increases the temperature by
∆𝑇 which induces a change ∆𝑃 in its
polarization. The change ∆𝑃 gives rise to
change ∆𝑉 in voltage that can be measure
with voltmeter across the crystal.
 Application of pyro electric materials:-
1) Pyro electric crystal are widely used as
infrared detectors.
2) Any infrared radiation that can raise the
crystal even by
1
1000
of a degree can be
detected.

14.  Ferro-Electric Materials
Joseph Valasek (27 April 1897 – 4 October
1993) was an American physicist and
professor emeritus of physics at
the University of Minnesota. He specialized
in geometrical and physical optics,
experimental optics and spectroscopy, and x-
rays. He is credited with the discovery
of ferroelectricity, which he identified
using Rochelle salts.

15.  Ferro-Electric Materials

17.  Dielectric loss

18.  Loss tangent

19.  conclusion
In conclusion, the Clausius-Mossotti Equation serves as a
valuable tool in understanding the behavior of dielectric
materials, especially in the context of piezoelectric, pyroelectric,
and ferroelectric materials. The study of dielectric loss and loss
tangent further enhances our comprehension of the efficiency
and performance of these materials in various applications,
contributing to advancements in electronic and technological
fields.

20.  references
Class Notes
www.google.com
www.Wikipedia.com
www.images.google.com
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control