Clausius Mossotti Equation.pptx

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 Inverse piezoelectric effect (electrostriction) 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 Piezoelectric Effect  

11. Direct Piezoelectric Effect   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 Piezoelectric Materials   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 w hich induces a chang e in its polarization. The change gives ris e to change in voltage that can be measure with voltmeter across the crystal. Application of pyro electric materials :- Pyro electric crystal are widely used as infrared detectors. Any infrared radiation that can raise the crystal even by 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  

16. Dielectric loss

17. Loss tangent

18. 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.

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