Can a Liquid be Magnet?

Magnetism is caused by domain alignment in crystal of material. When artificial magnets are formed . domain alignment is made possible by strong external magnetic field for ferromagnetic materials ferrofluid is molten ferromagnetic material which gets polarized as we apply magnetic field around it. Earth’s core has two parts inner solid core and outer fluid iron. The outer core rotates around inner core. Moving metals with charge causes magnetism, this is what Faraday’s Law speaks about.

However ferrofluids are referred to as a liquid magnet. Ferrofluids are colloidal mixtures of magnetic particles (~10 nm in diameter) in a liquid carrier. A typical ferrofluid is about 5% magnetic solids, 10% surfactant, and 85% carrier, by volume. In Electronics, Ferrofluids are used to form liquid seals around the spinning drive shafts in hard disks. The friction-reducing capabilities of Ferrofluids makes them usable in Mechanical Engineering.

There is another substance. Magnetorheological fluid or MR Fluid. When subjected to a magnetic field, the viscosity of the fluid increases to the extent of becoming a viscoelastic solid. Thus the ability to transmit force can be controlled with an electromagnet, which gives rise to its many possible control-based applications.