Characteristics of Diamagnetic, Paramagnetic and Ferromagnetic substances
September 23, 2020
A) Diamagnetic Substances and its characteristics
- Diamagnetic substances are those substances which, in their normal states, have no magnetic moment at all.
- Antimony, Bismuth, Copper, Gold, Mercury, water, alcohol, Hydrogen are diamagnetic substances.
Characteristics
- They are feebly repelled by magnet and magnetic field.
- When placed in a magnetic field, they all are weakly magnetized in a direction opposite to that of applied magnetic field.
- They tend to move from stronger to weaker magnetic field.
- When a diamagnetic bar is suspended freely in a magnetic field, it sets itself at right angle to the applied field.
- The flux density inside a diamagnetic substance kept in a magnetic field is slightly less than that in the free space. Hence the relative permeability is slightly less than one.
- The susceptibility has small negative value.
- The diamagnetic properties of a substance is independent of temperature.
- They do not obey Curie’s law.
- The diamagnetic liquid level in a limb of a U-tube placed in a magnetic field gets depressed.
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B) Paramagnetic substances and its characteristics
- Those substances which, in their normal state, have a non-zero magnetic moment are called paramagnetic substances.
- Aluminum, Chromium, Magnesia, Platinum, Oxygen, solutions of salts of nickel and iron etc. are paramagnetic substances.
Characteristics
- They are feebly attracted by magnet and magnetic field.
- When placed in a magnetic field, they are weakly magnetized in the direction of applied magnetic field.
- They tend to move from weaker to stronger magnetic field.
- When a paramagnetic bar is suspended freely in a magnetic field, it sets itself along the applied field.
- The flux density inside a paramagnetic substance kept in a magnetic field is slightly greater than that in the free space. Hence the relative permeability is slightly greater than one.
- The susceptibility has small positive value.
- The paramagnetic properties of a substance depend upon temperature.
- The susceptibility decreases with the rise in temperature.
- The paramagnetic liquid in a limb of U-tube, placed in a magnetic field is seen to rise.
C) Ferromagnetic substances and its characteristics
- Those substances which, in their normal states, have magnetic moment of high degree are called ferromagnetic substances.
- Iron, Cobalt, Nickel, Gadolinium, and their alloys are ferromagnetic substances.
Characteristics
- They are strongly attracted by magnet and magnetic field.
- When placed even in a weak magnetic field, they are strongly magnetized in the direction of applied magnetic field.
- They tend to move quickly from weaker to stronger magnetic field.
- When a ferromagnetic bar is suspended freely in a magnetic field, it sets itself quickly along the applied field.
- The flux density inside a ferromagnetic substance kept in a magnetic field is larger than that in the free space. Hence the relative permeability is very high.
- The susceptibility has large positive value.
- With increase in temperature, the ferromagnetism decreases.
- The susceptibility decreases with rise in temperature and at a critical temperature, called Curie point, ferromagnetic materials become paramagnetic.
References:
ii) https://pediaa.com/difference-between-diamagnetism-paramagnetism-and-ferromagnetism/
iii) https://www.differencebetween.com/difference-between-dia-and-vs-para-and-vs-ferromagnetic-materials/