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Question
Explain the following with suitable examples:
Antiferromagnetism
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Solution
The presence of unpaired electrons predicts paramagnetism or ferromagnetism in antiferromagnetic substances, despite their net zero magnetic moment.
Antiferromagnetic substances have domain structures similar to ferromagnetic substances but are oppositely orientated. The oppositely orientated domains cancel out each other’s magnetic moments.
Antiferromagnetism comes when magnetic moments align in a compensating fashion, yielding a zero net moment. MnO is a substance of this class.
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What type of magnetism is shown by a substance if magnetic moments of domains are arranged in same direction?
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Ferromagnetism
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Explain the following with suitable examples:
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Give reasons:Ferrimagnetic substances show better magnetism than antiferromagnetic substances.
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Fe3O4 is ____________.
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Fe3O4 (magnetite) is an example of ___________.
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(i) get oriented in the direction of the applied magnetic field.
(ii) get oriented opposite to the direction of the applied magnetic field.
(iii) are oppositely oriented with respect to each other without the application of magnetic field.
(iv) cancel out each other’s magnetic moment.
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(ii) Ferrimagnetic substances do not lose ferrimagnetism on heating and remain ferrimagnetic.
(iii) Antiferromagnetic substances have domain structures similar to ferromagnetic substances and their magnetic moments are not cancelled by each other.
(iv) In ferromagnetic substances all the domains get oriented in the direction of magnetic field and remain as such even after removing magnetic field.
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The heat of combustion of a substance is:
Some of the polar crystals when heated produces small electrical current. This phenomenon is called ______.
The correct order of bond strength is ______.
The value of aluminium susceptibility is 2.2 × 10-5. The percentage increase in the magnetic field if space within a current carrying toroid is filled with aluminium is `"x"/10^4`. Then the value of x is ______.
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The metal complex ion that is paramagnetic is ______.
(Atomic number of Fe = 26, Cu = 29, Co = 27 and Ni = 28)
