
8
Magnetic Systems
8.1 Introduction
A magnet is such an integral part of our world that it is natural to expect thermody-
namics to play a role in its description, or more generally, in the description of mag-
netic systems. That temperature has a central role to play in magnetism is revealed
by the fact that magnets lose their magnetism when heated. The power of thermo-
dynamics, as we have amply demonstrated so far, is in providing a fairly detailed,
and even quantitative, description of a system without invoking much of the micro-
scopic characterstics of the system. For the thermodynamics of magnetic systems too
we would like to achieve the same. ...