A common question those who are new to metals might wonder is: are all metals magnetic? The long and short of it is no, not all metals are magnetic but, magnetic material are always made of metal. Confusing right? Let’s simplify it. Iron is magnetic, so any metal with iron in it will be attracted to a magnet. Steel contains iron, so a steel paperclip will be attracted to a magnet too. Most other metals, like aluminum and copper are not magnetic. Certain metals have a strong magnetic field, others have none. It is important to comprehend magnetism's scientific principles, particularly when working with electronic waste (E-waste) and selling scrap metal.
The Role of Electrons in Magnetism
Let's go back to high school science. Remember electrons? They're the negatively charged parts of atoms. There are two types: free electrons and bound electrons. Metals have both. Electricity flows through metals because free electrons can move between atoms. But bound electrons stay inside atoms and can't move on their own. Simply put, metals can attract or repel magnetic things because of their magnetic properties. This happens because magnetic forces can go through different materials. A metal's magnetic properties affect its value and usefulness.
The Physics Behind Magnetic Metals
Metals' magnetic properties result from an unbalanced distribution of electrons inside their atoms. Magnetic poles are produced because of the erratic rotation and movement of electrons caused by this imbalance. The metal becomes magnetic when these dipoles line up and face in the same direction. The more dipoles facing the same direction, the stronger the magnetism.
Types of Magnetic Metals
Metals are divided into three types:
Ferromagnetic Metals: These metals have a strong magnetic field and are drawn to magnets Most importantly; they continue to be magnetic even after being exposed to a magnetic field. In simple terms, if something remains magnetic even after being near a magnet, it means it can keep its magnetic properties. It's like if you have a toy that sticks to a magnet, and even after you take it away, the toy can still stick to other magnetic things because it became a little magnet itself. So, when something stays magnetic after being around a magnet, we say it retains its magnetic properties. A well-known example of a ferromagnetic metal is iron.
Paramagnetic Metals: When exposed to a magnetic field, paramagnetic metals are only weakly attracted to magnets and lose their magnetic characteristics. When paramagnetic metals are near a magnet, they become a little bit magnetic themselves and get weakly attracted to the magnet. But once you take away the magnet, they lose this magnetic effect. So, the magnetic characteristics here refer to the temporary magnetism that these metals show only when they're close to a magnet. This group includes metals like aluminum and platinum.
Diamagnetic Metals: Diamagnetic metals are weakly magnetic as they offer only a slight resistance to both the north and south magnetic poles. Examples include gold, silver, and lead in e-waste.
Types of Magnetism
Metals are further distinguished by how long they maintain their magnetic characteristics. Metals can display magnetism in three different ways:
Electromagnetics: Metals that act as magnets only when an electric current passes through them are known as electromagnets. When the current stops, there is no longer a magnetic field.
Permanent magnets: Materials with lots of free electrons produce their magnetic charge on their own.
Transient Magnets: A few metals only exhibit magnetic characteristics when subjected to a powerful magnetic field. A metal having transient magnetic characteristics is steel, for instance.
Magnetic Metals in Focus
Several well-known metals having magnetic characteristics are listed below:
Iron: Iron is the most powerful ferromagnetic metal. It is essential to the Earth's magnetic field.
Nickel: Nickel, another ferromagnetic metal that is frequently employed in a variety of applications, is essential for the creation of powerful magnets like ALNICO magnets.
Cobalt: Both hard and soft magnets are made of cobalt, a substantial ferromagnetic metal.
Steel: While certain varieties of steel are magnetic, others are not. The magnetic properties of steel are influenced by the presence of chromium, much like in stainless steel alloys.
Non-Magnetic Metals
While certain metals have magnetic characteristics, the bulk of metals don't have them. Here are a few examples.
Aluminum: Because it lacks powerful magnetic characteristics, aluminum is a paramagnetic metal. It is renowned for its ability to resist corrosion.
Gold is a diamagnetic metal with a little magnetic push. Since real gold is not magnetic, it can be identified from fake gold.
Silver: Because silver is non-magnetic and does not attract magnets, it is simple to recognize in a variety of applications.
Copper: Copper is not naturally magnetic, but it can show a weak reaction when near strong magnets. This happens because the magnet's field can create small electric currents in the copper, causing a slight repulsion. It is essential in power production facilities because of its capacity to produce energy.
There is a close relationship between the behavior of the metals' electrons and their magnetic characteristics. The alignment of magnetic domains determines the intensity of the magnetism, which is present in metals with unpaired or weakly bound electrons. Understanding metal magnetism is crucial in a variety of sectors, such as recycling and managing electronic waste, as it has a substantial influence on the price and suitability of metals for diverse uses.