10 Examples of Magnetic Materials

The magnetic materials They are those that naturally possess attractive or repulsive properties over other materials. For instance: iron, nickel, cobalt, ferrite.

The phenomenon of attraction and repulsion between materials is called magnetism and is a part of electromagnetism (the field of physics that combines electrical and magnetic phenomena). A magnetic field is a mathematical model that explains the magnetic interaction between electric currents and magnetic materials. Magnetism occurs when materials are under the influence of a magnetic field.

Magnetic materials have been studied by man since ancient times and today are used in numerous industrial and everyday applications. They are easily recognized as they respond to the presence of a magnet (in fact, they are used to build magnets) or an electromagnet (an electrical circuit capable of generating magnetic fields).

Types of magnetic materials

They know each other various types of magnetic materials, each one with a particular response to the stimuli of a magnetic field, and they are:

  • Diamagnetic. Materials that repel magnetic fields through low intensity forces that, eventually, can be changed transiently.
  • Paramagnetic. Materials capable of responding to the action of a magnetic field, being attracted but unable to be permanently magnetized. If the paramagnetic properties of the magnetic field are removed, they simply disappear.
  • Ferromagnetic. Strongly magnetic materials, linked to iron and other metals, which under normal conditions are attracted by a magnetic field and retain magnetism. However, when heated above the Curie temperature (temperature at which a ferromagnetic material becomes paramagnetic), they become paramagnetic.
  • Ferrimagnetic. Materials usually derived from ferrite and ceramic type. They are susceptible to permanent magnetization or by saturation (when this happens, the magnetization does not increase any more although the strength of the magnetic field increases), just like ferromagnetic ones, but with less intensity. They also become paramagnetic when heated above the Curie Temperature.
  • Superparamagnetic. Ferromagnetic materials that are in suspension in a dielectric matrix (material with low electrical conductivity) and, therefore, retain some characteristics of ferromagnetic and others of paramagnetic.
  • Ferrites. Ceramic materials with low electrical conductivity. They are very powerful magnets that respond strongly to magnetic fields, even more than iron.
  • Non-magnetic. Materials that do not affect the lines of a magnetic field at all, that is, they do not respond to magnetism in any way.
  • Antiferromagnetic. Materials that reject magnetization, even under the effect of an induced magnetic field, no matter how powerful.

Finally, it should be clarified that practically all matter responds in some way to the presence of magnetic forces, only that it does not do so in the same way or with the same degree of intensity.

Examples of magnetic materials

  1. Iron (Faith). It is the ferromagnetic material par excellence. It is an extremely abundant transition metal on the planet (the only metal more abundant than iron is aluminum). The core of the Earth is made of this metal in a liquid state and, precisely, it is its movement that generates the magnetic poles of the planet that serve the compasses for its operation.
  2. Cobalt (Co). It is a bluish-white metal with ferromagnetic properties, which is usually found together with nickel, both on earth and in iron meteorites. It has numerous oxidation states, which allow it to constitute various metal compounds that at low temperatures are shown, on the other hand, as antiferromagnetic: cobalt (II) oxide (CoO) and dicobalt tetraoxide (Co3O4).
  3. Nickel (Neither). It is a yellowish-white transition metal, it is very ductile and malleable and a great conductor of electricity and heat, so it is ferromagnetic at room temperature. In many cases, it shares characteristics with iron but is much more resistant to corrosion than iron.
  4. Bismuth (Bi). It is a very rare metallic chemical element, like silver. a It is one of the most strongly diamagnetic (resistant to magnetization) that exists, it is a poor conductor of electricity and heat, and in a magnetic field it can increase its electrical resistance, and be useful to measure the intensity of the forces in that field. countryside.
  5. Germanium (Ge). It is a greyish-white semi-metal, resistant to acids and alkalis, which has the same crystalline structure as diamond. Since its properties are considered intermediate between metals and non-metals, this element is diamagnetic, despite being a semiconductor of electricity.
  6. Graphite (C). It is one of the forms of appearance of carbon (along with coal and diamond). It is black, shiny, poorly conductive of electricity, and therefore diamagnetic, operating as a semiconductor at best.
  7. Noble gases (halogens). They are a set of elements in the periodic table that have a very low reactivity with any other substance, which is why they are often called “inert”. Helium, argon, krypton, neon and others are some examples. In the presence of magnetic fields they are diamagnetic.
  8. Magnesium (Mg). Although it is not found in free form in nature (but as part of other compounds (magnesium is a light, water-insoluble, silvery-white, highly flammable metal that has paramagnetic properties.
  9. Ferrite. Ferrite is a ceramic material that responds very strongly to magnetic fields, even more than iron, which allows it to be used to magnetize other materials and produce magnets, for example.
  10. Mild steel. Steel is an alloy of iron with other metallic elements (such as nickel, cobalt or copper) or non-metallic elements (such as carbon or sulfur) and, therefore, retains many of its properties, depending on the percentage of mixture it exhibits. . Mild steel contains carbon levels between 0.15 and 0.25%, that is, almost pure iron, and retains many of its ferromagnetic properties.