Domain theory of ferromagnetism

Answer 1

domain is a aggregate of several electrons about 10 raised to 16 , in the case of ferromagnetic substances.but the electrons are in random motion,and so net magnetic moment is 0. but when weak external magnetic field is applied,one domain increases in size at the cost of other domains and in this domain the e's align themselves in direction of field.but in strong external field,all domain remain same and electrons of all domain arrange in direction of magnetic field.so strong net magnetic moment created and substance behaves as strong magnet

Answer 2

The domain theory explains that an elements ability to be magnetic is governed by atomic structure. Magnetization occurs as a result of the behavior of that elements electrons. As each electron orbits the nucleus it it also spins on its axis, much like the planets around the sun. Magnetization occurs as the result of the electron spinning on its axis in different directions. If the element has 5 electrons spinning clockwise and 5 spinning anti-clockwise the element will be neutral. However if the element has 4 spinning clockwise and 5 spinning anti-clockwise the balance is shifted and the element will be magnetized.

Answer 3

the ferromagnetic material is composed from small regions which are called domains. in each domain the atomicdipoles aligned to each other in specified direction and this is because exchange interaction between the electrons in the atoms Heisenberg's theory of ferromagnetism" in older it is called main field "molecular field" Weiss's theory"

Answer 4

all the molecules of a magnetic substance is an independent magnet. in an unmagnetized magnetic substance, the molecular magnets are randomly oriented. they form dosed chains so they neutralize the effect of each other. these chains are called domains and each molecular magnet is called dipole.

when a substance is magnetized, the molecular magnets are arranged in one direction by breaking the domains. the end where all the north poles of the dipoles are present becomes the north pole of the magnet. the other end where south pole of the dipoles are present becomes the south pole of the magnet.

when the magnet is strongly heated or hammered the kinetic energy of the molecules increases and therefore the molecules alignment gets disrupted and the molecules go back to the closed chain arrangement to form domains and thus the magnet gets demagnetized :) thank you.

Answer 5

who suggested the

molecular theory of magnetism