Question

Compare and contrast, using a diagram or otherwise, how the magnetic domains align in an applied magnetic field for diamagnetic, paramagnetic, and ferromagnetic materials. Give an indication of the magnetic susceptibilities in each case. Estimate the saturation magnetisation (units A/m) for Nickel assuming 0.6 Bohr Magnetons per atom and a density of 8.91 gcm-3.

Answer 1

The saturation magnetization is given by Ms = 0.6μBN, where N is the number of atoms/m3.
But
N= ρNa/ANi, where ρ is the density and ANi is the atomic weight of Ni.
So

N=(8.90* 10^6 g/m )*(6.02* 10^23 atoms/mol) /58.7 g/mol
N = = 9.13 × 1028 atoms/m3.
Then Ms = 0.6 (9.27 × 10^-24)( 9.13 × 10^28) = 5.1 × 10^5 A/m.

Diamagnetic materials have a weak, negative susceptibility to magnetic fields. Diamagnetic materials are marginally repulsed by a magnetic field and the material does not hold the magnetic properties when the outside field is evacuated. In diamagnetic materials all the electron are combined so there is no changeless net magnetic minute per molecule. Diamagnetic properties emerge from the realignment of the electron ways affected by an outside magnetic field. Most components in the occasional table, including copper, silver, and gold, are diamagnetic.

Paramagnetic materials have a little, positive susceptibility to magnetic fields. These materials are marginally pulled in by a magnetic field and the material does not hold the magnetic properties when the outside field is evacuated. Paramagnetic properties are because of the nearness of some unpaired electrons, and from the realignment of the electron ways caused by the outer magnetic field. Paramagnetic materials incorporate magnesium, molybdenum, lithium, and tantalum.

Ferromagnetic materials have a huge, positive susceptibility to an outer magnetic field. They show a solid appreciation for magnetic fields and can hold their magnetic properties after the outside field has been expelled. Ferromagnetic materials have some unpaired electrons so their iotas have a net magnetic minute. They get their solid magnetic properties because of the nearness of magnetic areas. In these areas, vast quantities of particle's minutes (1012 to 1015) are adjusted parallel so the magnetic power inside the space is solid. At the point when a ferromagnetic material is in the unmagnetized express, the areas are almost haphazardly sorted out and the net magnetic field for the part, in general, is zero. At the point when a polarizing power is connected, the spaces wind up adjusted to deliver a solid magnetic field inside the part. Iron, nickel, and cobalt are models of ferromagnetic materials. Segments with these materials are regularly assessed utilizing the magnetic molecule strategy.