3.2 A magnetic specimen consists of N atoms, each having a magnetic moment . In an applied...

3.2 A magnetic specimen consists of N atoms, each having a magnetic moment μ. In an applied homogeneous magnetic field each atom may orient itself parallel or antiparallel to the field, the energy of an atom in the two orientations being respectively. Here θ is a temperature characteristic of the specimen, is its magnetic moment, and μ0 is the permeability of the vacuum. Show that the magnetic moment of the specimen at temperature T is given by If μN, obtain the temperature dependence of the magnetic susceptibility per atom, χ = / N.

Sketch the temperature dependence of the magnetic moment in zero field ( = 0).

What sort of material is represented by these equations?