The analogue of molecular electronics for electron spin. Spintronics is the branch of electronics concerned with the transport phenomena of electrons and especially their spin. When research into spintronics began in the late 1980s it made use of solids, such as the Heusler alloys, and certain inorganic semiconductors, such as gallium arsenide. Molecular spintronics developed in the late 1990s, with materials such as fullerenes and graphene being intensively investigated. There are many possible applications of molecular spintronics, just as with solid spintronics.