This document discusses the properties of ferrimagnetic materials. It defines ferrites as ceramic-like materials with magnetic properties that are used in electronic devices. Soft ferrites are used in transformer cores while hard ferrites are used in refrigerator magnets. The document discusses the B-H curve formation and Curie temperature of ferrimagnetic materials. It provides the Curie temperatures of different materials and describes the working of an apparatus used to measure Curie temperature. Finally, it outlines some applications of ferrites such as in microwave frequency devices, computer memory, and magnetic recording heads.

2. Submitted By:-
Isha Garg 301604014
Isha Kalra 301604015
Jagmeet Kaur 301604016
Jaspreet Kaur 301604018

3. CONTENTS
• PROPERTIES OF FERRIMAGNETIC MATERIALS
 B-H CURVE FORMATION
 CURIE TEMPERATURE
 TC OF DIFFERENT MATERIALS
 APPARATUS WORKING
 APPLICATIONS

4. What are Ferrites
• Ferrite is a ceramic-like material with magnetic
properties, which is used in many types of electronic
devices.
 Soft ferrites - used in transformer or electromagnetic cores.
They have a low coercivity (manganese-zinc ferrite, nickel-
zinc ferrite).
 Hard ferrites- have a high coercivity. They are cheap, and
are widely used in household products such as refrigerator
magnets (strontium ferrite, barium ferrite).

5. Ferrites have importance in engineering and technology because they possess
spontaneous magnetic moment below the Curie temperature just as iron, cobalt,
nickel.
Due to vey low eddy current losses, ferrites are used as a core of coils in
microwave frequency devices and computer memory core elements.
Due to relatively low permeability and flux density compared to iron, ferrites
are not suitable for the use in high field and high power applications, such as
motors, generators and power transformers, but they can be used in low field and
low power applications.
Ferrites are used as ferromagnetic insulators in electrical circuits.
Ferrites like ZnO find low frequency applications in timers. They are also used as
switches in refrigerators, air conditioners, etc.
Ferrites are used as magnetic head transducer in recording.
Applications of ferrites

6. Ferromagnetic Ferrimagnetic

8. 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. TC OF DIFFERENT MATERIALS

11. The CuriE Weiss law describes the magnetic
susceptibility χ of a FERROMAGNET in
the paramagnetic region above the Curie POINT
χ= C
T- Tc
where C is a material-specific Curie constant T is absolute
temperature, measured in kelvins, and Tc is the Curie
temperature measured in kelvin. The law predicts a singularity
in the susceptibility at T = Tc. Below this temperature the
ferromagnet has a spontaneous magnetization

12. WORKING & APPARATUS

13. CROHOT OIL OVEN CURIE TEMPERATURE
KIT
APPARATUS

14. CURIE TEMPERATURE = 150⁰C

16. TEMPERATURE
V
O
L
T
A
G
E

17. CURIE CONSTANT=0.14/0.067=
2.09

18. APPLICATIONS OF CURIE POINT

19.  It is an instrument used for measuring the working speed of an particular
machine or engine. OR Measures revolution speed of any rotating object such
as motor or shaft.
The basic reason behind having a tacho is to learn how your engine is
performing at any given point of time. Tachometer indicates revolutions per
minute(RPM) of that object.
In analogue audio recording , a tachometer is a device that measures the
speed of audiotape as it passes across the head.
TACHOMETER

20. Temperature Controlled Soldering Iron
Our approach is to use magnetized soldering tips
which lose their magnetic properties at a specific
temperature, the curie point. As long as the tip is
magnetic, it closes a switch to supply power to the
heating element. When it exceeds the design
temperature it opens the contacts, cooling until the
temperature drops enough to restore magnetisation.

21. Magneto-optical drive
A magneto-optical drive is a kind
of optical disc drive capable of writing
and rewriting data upon a magneto-
optical DISC.