Magnetic materials are substances that are strongly attracted to a magnet. The most common magnetic materials are iron, nickel, and cobalt — called ferromagnetic materials. Non-magnetic materials such as copper, aluminium, wood, plastic, and brass are not attracted to magnets under normal conditions. In physics, materials are classified into three categories based on their response to magnetic fields: ferromagnetic (strongly attracted), paramagnetic (weakly attracted), and diamagnetic (weakly repelled).
Ferromagnetic materials: iron (Fe), nickel (Ni), cobalt (Co) — strongly attracted to magnets.
Paramagnetic: aluminium, platinum, chromium, oxygen — weakly attracted; practically non-magnetic in daily life.
Diamagnetic: copper, gold, silver, zinc, bismuth, wood, plastic, glass — weakly repelled.
Steel is magnetic (iron alloy). Brass (copper + zinc) is non-magnetic.
Ferromagnetism due to unpaired electrons and magnetic domain alignment.
In everyday life and school exams: copper, aluminium, brass, wood, plastic = non-magnetic.
Iron, nickel, cobalt, steel, and their alloys are magnetic.
Above the Curie temperature (770°C for iron), ferromagnets become paramagnetic.
Ferromagnetic materials (strongly magnetic): • Strongly attracted to magnets • Can be permanently magnetised • Examples: iron (Fe), nickel (Ni), cobalt (Co), gadolinium (Gd), and their alloys • Steel (iron alloy) is ferromagnetic • Why? They have unpaired electrons and magnetic 'domains' — regions where atomic magnets align. When placed in a field, the domains align → strong magnetisation
Paramagnetic materials (weakly magnetic): • Weakly attracted to magnets • Cannot be permanently magnetised — lose magnetism when field is removed • Examples: aluminium (Al), platinum (Pt), chromium (Cr), oxygen (O₂), sodium, magnesium • In everyday experiments, these behave as 'non-magnetic' • Why? Have unpaired electrons but no magnetic domains; only weakly align in a field
Diamagnetic materials (weakly repelled): • Weakly repelled by magnets (pushed away from strong magnetic fields) • All electrons are paired — no net magnetic moment • Examples: copper (Cu), gold (Au), silver (Ag), bismuth (Bi), zinc (Zn), water (H₂O), wood, plastic, glass, mercury • Most non-metals and many metals are diamagnetic
In everyday and exam contexts, these materials are considered non-magnetic:
Material | Category | Magnetic response Copper (Cu) | Diamagnetic | Not attracted to magnets (used in wires) Aluminium (Al) | Paramagnetic | Practically non-magnetic Brass (Cu + Zn alloy) | Diamagnetic | Not magnetic Zinc (Zn) | Diamagnetic | Not magnetic Silver (Ag) | Diamagnetic | Not magnetic Gold (Au) | Diamagnetic | Not magnetic Wood | Diamagnetic | Not magnetic Plastic | Diamagnetic | Not magnetic Glass | Diamagnetic | Not magnetic Rubber | Diamagnetic | Not magnetic Mercury | Diamagnetic | Not magnetic
Common MCQ check: • Iron, nickel, cobalt, steel → MAGNETIC • Copper, aluminium, brass, wood, plastic, glass → NOT magnetic
Magnetism in materials comes from the electrons:
Unpaired electrons create a magnetic moment: • Each electron acts like a tiny bar magnet due to its spin • In atoms with unpaired electrons, the magnetic moments do not cancel → net magnetic moment • Iron has 4 unpaired electrons → strong magnetic moment per atom
Magnetic domains (ferromagnets): • In ferromagnetic materials (Fe, Ni, Co), groups of atoms — called domains — align their magnetic moments in the same direction • Unmagnetised iron: domains point in random directions → no net magnetism • In a magnetic field: domains align → strong magnetism • After field is removed: domains partially retain alignment → permanent magnet
No unpaired electrons → diamagnetic: • Materials where all electrons are paired (like copper, gold) have equal and opposite magnetic moments that cancel → no net magnetism → repelled very weakly
Curie temperature: • Above this temperature, ferromagnetic materials lose their magnetism (become paramagnetic) • Curie temperature of iron: 770°C
Copper (Cu) is not a magnetic material. Iron, nickel, and cobalt are ferromagnetic — they are strongly attracted to magnets. Copper is diamagnetic — it is not attracted to magnets and is in fact very weakly repelled by a magnetic field. Copper is a non-magnetic material.
1. Ferromagnetic: strongly attracted to magnets; can be permanently magnetised. Examples: iron, nickel, cobalt, steel. 2. Paramagnetic: weakly attracted to magnets; lose magnetism when field is removed. Examples: aluminium, platinum, chromium, oxygen. 3. Diamagnetic: weakly repelled by magnets. Examples: copper, gold, silver, wood, plastic, glass, water.
Aluminium (Al) is paramagnetic — it is very weakly attracted to a strong magnetic field. However, in everyday experiments, this effect is too weak to be noticeable. For practical purposes in school science, aluminium is treated as a non-magnetic material. It cannot be attracted by an ordinary bar magnet.
Copper (Cu) is diamagnetic — all its electrons are paired, so the magnetic moments of individual electrons cancel each other out. This means copper has no net magnetic moment and is not attracted to a magnet. Instead, it is very weakly repelled. Copper is widely used in electrical wiring precisely because it is a good conductor but not magnetic.
Brass (an alloy of copper and zinc) is not magnetic. Both copper (diamagnetic) and zinc (diamagnetic) are non-magnetic metals, so their alloy — brass — is also non-magnetic. Brass is not attracted to a magnet.
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