The most popular account for the discovery of magnets is a legend of a shepherd named Magnes who lived in Magnesia near Mount Ida in Greece Mount Ida was referred to as the "Mountain of the Goddess". Approximately 2,600 years ago (600 BC) while herding sheep on the mountain, Magnes found that the nails and buckle of his sandals and the tip of his staff were attracted to the rock he was standing on. He dug up the Earth to find lodestones. Lodestones contain magnetite, a natural magnetic material Fe3O4.
The word magnet is derived from the Greek name magnetis lithos, the stone of Magnesia, referring to the region on the Aegean coast in present-day Turkey where these magnetic stones were found.
Middle Ages History
The Chinese provide the first documented use of suspended lodestones used as a compass. In 1088 Shen Kuo described the magnetic needle compass, which could be used for navigation in his Dream Pool Essays. The first recorded use was documented by Zheng He of the Yunnan province. Between the years 1405 and 1433, Zheng He recorded his voyages across seven oceans.
In approximately 1180, Englishman Alexander Neckam records the earliest European understanding of the magnet as a guide to seamen, the early compass. The term lodestone comes from the Anglo-Saxon meaning "leading stone," or literally, "the stone that leads." The Icelandic word is leider-stein, and was used in writings of that period in reference to the navigation of ships.
In 1600, English scientist William Gilbert confirmed earlier observations regarding magnetic poles and concluded that the Earth was a magnet. In 1820, the Dutch scientist Hans Christian Oersted discovered the relationship between electricity and magnetism, and French physicist Andre Ampere further expanded upon this discovery in 1821.
In the early 1900s, scientists began studying magnetic materials other than those based on iron and steel. By the 1930s, researchers had produced the first powerful Alnico alloy permanent magnets.
In 1966 the first rare earth magnets were developed from Samarium-Cobalt (SmCo5) producing a high energy product of 18 MGOe. In 1972 further developments were made using Samarium-Cobalt (Sm2Co17) to produce a higher energy magnet product of 30 MGOe.
In 1983 General Motors, Sumitomo Special Metals and the Chinese Academy of Sciences developed a high energy product of 35 MGOe from a compound of Neodymium-Iron-Boron (Nd2Fe14B) referred to as neo magnets or rare earth magnets. The enormous interest these magnets have generated arises because, for the first time, a new magnetic material has been introduced which is not only stronger than the previous generation but is more efficient. Neo magnets are the strongest type of permanent magnet in the world.
Today magnets play a role almost every technologically advanced device we use, including computers, automobiles, industrial sorter and seperators, power generators, speakers, cell phones etc.