Solid State Physics

Chapter 11

Magnestim

11.1 INTRODUCTION

There are some materials that have special properties to attract each other. This property is called magnetism and the materials are called the magnets. The phenomenon of magnetism and many other experimental facts connected with it were known to the Greek and the Chinese more than 2,500 years ago. It was first noted by the Greeks that lodestone or magnetite or the magnetic materials that they had, attracted iron needles. Chinese (12th century) first made the lodestone compass needle and used it in navigation by employing the astronomical concept of true north. Later, it was found to be of tremendous use for seafaring nations in discovering our planet.

It was in 1819 that Hans Christian Oersted accidentally ...