Susceptibility of antiferromagnetic materials

The susceptibility of antiferromagnetic materials are small and positive. It increases with the rise in temperature. The susceptibility becomes maximum at Neel temperature and decreases with further rise in temperature.

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Neel temperature

The magnetisation of antiferromagnetic materials depends on temperature. The magnetisation increases with the rise in temperature and becomes maximum at a particular temperature. Above this particular temperature, magnetisation decreases. This particular temperature at which magnetisation is maximum is called Neel temperature. Above the Neel temperature, the anti-ferromagnetic material becomes paramagnetic.

Reference: This article is referred from my book “electrical engineering materials” having ISBN 978-81-272-5069-0

Examples of antiferromagnetic materials

In the presence of the strong magnetic field, antiferromagnetic materials are weakly magnetised in the direction the field. This property of the materials is called antiferromagnetism and the materials which exhibit this propert are called antiferromagnetic materials.

Examples of antiferromagnetic substances: MnO, FeO, CoO, NiO, Cr, Mn,

MnO4, MnS, FeCl3, MnF2

Reference: This article is referred from my book “electrical engineering materials” having ISBN 978-81-272-5069-0

Influence of magnetic field on antiferromagnetic materials

In the presence of the strong magnetic field, antiferromagnetic materials are weakly magnetised in the direction the field. This property of the materials is called antiferromagnetism and the materials which exhibit this propert are called antiferromagnetic materials.

Examples of antiferromagnetic substances: MnO, FeO, CoO, NiO, Cr, Mn.

Reference: This article is referred from my book “electrical engineering materials” having ISBN 978-81-272-5069-0

Who discovered antiferromagnetism

Antiferromagnetism was first discovered by Neel and Bitter and later extended by Van Vleck. Experimentally, antiferromagnetism was first observed as a property of MnO by Bizette, Squire and Tsai in 1938.

Reference: This article is referred from my book “electrical engineering materials” having ISBN 978-81-272-5069-0

Antiferromagnetic materials

Antiferromagnetism was first discovered by Neel and Bitter and later extended by Van Vleck. Experimentally, antiferromagnetism was first observed as a property of MnO by Bizette, Squire and Tsai in 1938.

Cause of antiferromagnetism: In antiferromagnetc materials, the magnetic moments are aligned in opposite directions and are equal in magnitude.

Thus, when antiferromagnetic material is unmagnetized its net magnetisation is zero because magnetic moments of the neighbouring atoms exactly cancel when they are vectorially added.

In the presence of the strong magnetic field, antiferromagnetic materials are weakly magnetised in the direction the field. This property of the materials is called antiferromagnetism and the materials which exhibit this propert are called antiferromagnetic materials.

Examples of antiferromagnetic substances: MnO, FeO, CoO, NiO, Cr, Mn.

Reference: This article is referred from my book “electrical engineering materials” having ISBN 978-81-272-5069-0

Spontaneous magnetization

The ferromagnetic materials possess  magnetic moment and thus magnetization even in the absence of the applied magnetic field, this magnetization is known as the spontaneous magnetization.

Spontaneous magnetization is stable only below a certain critical temperature called the Curies temperature, which is above the room temperature. Also, the spontaneous magnetization decreases as the temperature rises. But above the Curie temperature, the regular order of magnetic moments does not exist that is the atomic magnetic moments lie randomly oriented.

Reference: This article is referred from my book “electrical engineering materials” having ISBN 978-81-272-5069-0

Ferrimagnetic materials

In ferrimagnetic materials, the magnetic moments of unequal magnitude are aligned in opposite directions so that net magnetisation occurs.

According to Neel, ferrimagnetism is the property of those materials which below a certain temperature called Neel temperature, show spontaneous magnetisation.

Reference: This article is referred from my book “electrical engineering materials” having ISBN 978-81-272-5069-0