Do liquid magnets exist?

Do liquid magnets exist?

Magnets are made of metals and their composites, but if melted at high temperatures they lose their magnetism. Despite this drawback, it is still possible to make magnetically sensitive liquids. Known as ferrofluids, they consist of extremely small particles of a ferromagnetic material such as iron oxide finely distributed in water or oil. Thanks to their size, the particles don't sink and so the the liquid as a whole becomes magnetic. There are many areas in which magnetic liquids can be used, from new sealing methods to modern lubricants. One great advantage is that a magnetic force will keep them  where they are needed. In addition, magnetic liquid may provide a useful tool in cancer therapies where they could embedded in the tissue of a tumour and then have their polarity constantly reversed. The rapid movement of the particles would lead to a build-up of heat, which would finally result in the destruction of the tumour tissue.