3.1 A crystal contains N atoms which possess spin 1 and magnetic moment . Placed in a...

3.1 A crystal contains N atoms which possess spin 1 and magnetic moment μ. Placed in a uniform magnetic field the atoms can orient themselves in three directions: parallel, perpendicular and antiparallel to the field. If the crystal is in thermal equilibrium at temperature T find an expression for its mean magnetic moment , assuming that only the interactions of the dipoles with the field need be considered.

What is the magnetic moment of the crystal (i) when placed in a weak field at high temperature, (ii) when placed in a strong field at low temperature?