What happens when a magnet is near different types of materials?

When the magnet is near different types of materials, different phenomena occur. These phenomena mainly depend on the magnetic properties of the material itself. Common materials can be divided into several categories: ferromagnetic materials, paramagnetic materials, diamagnetic materials and superconducting materials. Here's how these materials can change when a magnet is near:

Ferromagnetic material

Ferromagnetic materials, such as iron (Fe), nickel (Ni), cobalt (Co) and their alloys, have strong magnetic properties. When a magnet is near such a material:

• Attraction: Magnets will attract these materials because ferromagnetic materials will exhibit a strong magnetizing effect in a magnetic field.

• Magnetic domain alignment: The magnetic field of the magnet will cause the magnetic domains in the material to tend to be neatly aligned, thus enhancing the overall magnetic properties of the material.

• Hysteresis effect: After the magnet is removed, part of the magnetization may remain, a phenomenon known as hysteresis.

Paramagnetic material

Paramagnetic materials, such as aluminum (Al), chromium (Cr), manganese (Mn), etc., have weak magnetism. When a magnet is near such a material:

• Weak attraction: These materials are slightly attracted because the unpaired electrons in them are affected by the external magnetic field, resulting in a magnetic moment.

• Non-permanent magnetism: Once the magnet is removed, the magnetic effect in the paramagnetic material will disappear.

Diamagnetic material

Diamagnetic materials, such as silver (Ag), gold (Au), copper (Cu), etc., have weak magnetic repelling properties. When a magnet is near such a material:

• Weak repulsion: These materials exhibit weak repulsion because the orbits of electrons in them generate small magnetic moments in the direction opposite to the external magnetic field.

• Non-magnetic: diamagnetic materials do not have magnetic properties themselves, so they are not attracted to magnets.

Superconducting material

Superconducting materials exhibit the property of completely repelling magnetic fields at low temperatures, known as the Meissner effect. When a magnet is near such a material:

• Complete repulsion: In the superconducting state, the material repels all external magnetic fields so that they cannot penetrate the inside of the material.

• Suspension effect: Superconductors can be suspended in the air under strong magnetic fields due to complete repulsion caused by the Meissner effect.

Non-magnetic material

For non-magnetic materials, such as plastic, wood, etc., there is basically no significant change when the magnet is near, because these materials neither attract nor repel the magnetic field.

Sum up

When the magnet is close to different types of materials, the phenomenon observed depends on the magnetic properties of the material. Ferromagnetic materials are strongly attracted and may retain some magnetism; Paramagnetic materials will have a weak attraction; Diamagnetic materials will have a weak repulsion; Superconducting materials can completely repel magnetic field and suspend under certain conditions. And non-magnetic materials will not have a significant change. Understanding the response of these different materials is critical for magnetic applications and technologies.