Q 1.24:What type of substances would make better permanent magnets, ferromagnetic or ferrimagnetic. Justify your Solution:.

Q 1.24:What type of substances would make better permanent magnets, ferromagnetic or ferrimagnetic. Justify your Solution:.

Solution:

Ferromagnetic substances would make better permanent magnets. A few substances like iron, cobalt, nickel, gadolinium and CrO2 are attracted very strongly by a magnetic field. Such substances are called ferromagnetic substances.Besides strong attractions, these substances can be permanently magnetised. In solid state, the metal ions of ferromagnetic substances are grouped together into small regions called domains. Thus, each domain acts as a tiny magnet. In an unmagnetised piece of a ferromagnetic substance the domains are randomly oriented and their magnetic moments get cancelled. When the substance is placed in a magnetic field all the domains get oriented in the direction of the magnetic field (and a strong magnetic effect is produced. This ordering of domains persist even when the magnetic field is removed and the ferromagnetic substance becomes a permanent magnet.