The most popular and natural materials that exhibit that property include; nickel, cobalt, iron and their alloys. And when iron is heated red hot ,a magnet wont stick to it . However, blood is not magnetic in a conventional sense. Ferromagnetism is the type of magnetism exhibited by iron, nickel, and cobalt. Why then, does the molten iron in Earth’s core produce a magnetic field? Antiferromagnetism plays a crucial role in giant magnetoresistance, as had been discovered in 1988 by the Nobel prize winners Albert Fert and Peter Grünberg (awarded in 2007) using synthetic antiferromagnets. Now this is a really complex subject... first, magnetism is actually divided on a bunch of "classes", some elements are diamagnetic and will be repelled by a magnetic field, other are paramagnetic and are attracted by the field, and there are the ferromagnetic elements like iron, nickel and others, that become permanent magnetics upon being exposed to a mag. Ferromagnetic materials are also able to retain magnetization outside of an external current or magnetic field. Permalloy is an active, tunable material which can be used in microwave devices or in tiny, single chip electronics. Ferromagnetic materials are those that are strongly magnetized in an external magnetic field, and retain their magnetic moment even after the magnetic field is removed. By altering the ratio of iron and nickel in the composition, the properties of the permalloy can be subtly changed. Let’s start right from the bottom of this entire mystery. Ferromagnetic materials are materials that can easily be magnetized. The internal field in ferromagnetism may be a thousand times greater χ ≫ 1) than that of diamagnetic and paramagnetic materials. In other words, it is not ferromagnetic which is what most people understand as magnetism. Compared to paramagnetism and diamagnetism (covered in the next section), ferrormagnetism is several of orders of magnitude stronger. See the article in The Journal of Nuclear Physics, March, 2019 "Magnetism from iron's nuclear structure" Cobalt also has two loops. liquid oxygen is also magnetic , I would like to know what causes the magnetic field in a neutron. Ferromagnetic materials. This is why at the steel mill they have to pick up the slabs with tongs when they are hot , but when they cool you … The effect in iron is much stronger than in nickel or cobalt. Stuart - The fact that blood contains iron is one of the reasons why some people believe magnetic bracelets might have an effect on the human body. Nickel and Gadolinium are … Iron has a nucleus with two loops of protons coaxial with isolated protons. The results of the concentration-dependent ferromagnetic moments in ZnO systems have been given by Coey et al. Permalloy-based structures are ferromagnetic metals made of different proportions of iron and nickel.