Curie temperature of ferrites

This is very short introduction about ferrites, curie temperature and curie weiss law.

1. Curie temperature of Ferrites Name- Ashutosh Tiwari (M.Sc. Physics 2 nd year) Subject – Material science lab Submitted to Dr. R.S. Gedam Sir

2. The magnetic behavior of materials can be classified into the following five major groups:   1. Diamagnetism   2. Paramagnetism   3. Ferromagnetism   4. Ferrimagnetism or Ferrites* 5. Antiferromagnetism

3. What is ferrites ?? Ferrite is ceremic like material with magnetic properties and which is used in high frequency electrical components. Ferrite term is used to describe class of magnetic oxide compound that contain iron oxide as main principle component. The general chemical composition MO.Fe2O3, where M is a divalent metal such as Mn, Mg, Fe, Zn, Ni, Cd, etc.

4. The general chemical composition of ferrite , where M is a divalent metal such as Mn, Mg, Fe, Zn, Ni, Cd, etc.   Crystal structure of ferrite

5. B-H Curve hysteresis : B-H Curve Hysteresis :

6. Types of ferrites : Soft ferrite : Low coercivity means the material magnetization can easily reverse direction without dissipating much enegy (Hysteresis loss) while high resistivity prevent eddy current losses. Hard ferrite : High coercivity means material resist to demagnetized as in permanent magnets (ferromagnets). Due to high magnetic permeability these are called Ceramic magnet.

7. Curie Temperature • Curie point, also called Curie Temperature, temperature at which certain magnetic materials undergo a sharp change in their magnetic properties. • This temperature is named for the French physicist Pierre Curie, who in 1895 discovered the laws that relate some magnetic properties to change in temperature. • At low temperatures, magnetic dipoles are aligned. Above the curie point, random thermal motions nudge dipoles out of alignments.

9. Susceptibility , = =   Property Diamagnetic paramagnetic ferromagnetic   <0 (negative) does not depend on temperature   (positive but low) =   (positive and high) =  

10. Thank you …