Among many minerals, magnetite stands out for its magnetic properties. Natural magnetite can attract iron due to their mutual magnetic attraction. Can magnets attract metals other than iron?
Strictly speaking, yes. Magnets have attractive force on ferromagnetic metals like cobalt and nickel, in addition to iron. The workings of magnets are quite fascinating and often leave quantum mechanics experts mesmerized.
Physicists believe that ferromagnetic materials like iron have many unpaired electrons in their structure. When an external magnetic field is applied to them, they become “magnetized”, and the manifestation of this magnetization is their ability to be attracted by a magnet.
Magnets are one of the most common objects in our daily lives, yet explaining magnetism with conventional theories is not sufficient. Even if you were to bring Newton himself, he might not be able to explain the origin of magnetism. Only quantum mechanics can provide an explanation.
We know that there are four fundamental forces in the universe, and electromagnetism is one of them. Electromagnetic force can be divided into magnetic force and Coulomb force. These two forces have different paths but ultimately lead to the same result. Magnetic force is a type of “Coulomb force” generated by moving charges.
The basic building block of all common matter is the atom, which consists of a nucleus and electrons. Electrons move around the nucleus in fixed orbits according to quantum mechanics, and they possess a magnetic moment due to their movement. This magnetic moment results from the external effect of the electron’s motion.
When the movement of electrons in the atoms of a substance is very uniform and coordinated, the magnetic moments generated by their movement mostly cancel out, resulting in no magnetic properties or only weak magnetic properties.
However, atoms in the middle of the periodic table have an uneven distribution of electrons, resulting in magnetic properties. But not all of these atoms in the periodic table have the same level of magnetism as magnets do.
Having a magnetic moment is just the first step. With millions of atoms composing matter, these atoms randomly arrange themselves, leading to significant cancellation of their magnetic properties. Only substances with a special crystalline structure can form magnetic domains within the crystal, in which the atoms exhibit high magnetism. When subjected to a magnetic field, these magnetic domains align in the same direction and exhibit magnetism. Even after the magnetic field disappears, these magnetic domains can maintain a certain level of magnetism, creating what we commonly call artificial permanent magnets in our daily lives.
These substances have already been magnetized. In addition to iron, cobalt and nickel are also easily magnetized. We can find small permanent magnets like these in many electronic products. The study of electromagnetic force has become a key direction in quantum mechanics. Scientists have also discovered the laws of magnetism changes in magnets at high temperatures. Once the temperature reaches a certain level, the magnetism of the magnetized permanent magnet will disappear.
For example, magnetized iron loses its magnetism when heated to 770 degrees Celsius. Cobalt and nickel are also attracted by magnets, and their magnetic fields change under high-temperature conditions. What are your thoughts on this?