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Paramagnetism

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Also Known AsParamagnetic material, magnetic paramagnetism, Curie paramagnetism

What is Paramagnetism?

Paramagnetism is a form of magnetism in which a material is weakly attracted to an externally applied magnetic field. It arises from unpaired electrons in atoms, ions, or molecules, which have permanent magnetic moments that align partially with an applied field. Unlike ferromagnetism, paramagnetic behavior disappears when the external field is removed and is temperature-dependent (Curie law: χ ∝ 1/T).

Properties & Characteristics

Requires unpaired electrons. Weak attraction to external magnetic field. Susceptibility χ: small positive value. Curie law: χ = C/T (C = Curie constant, T = absolute temperature). Examples: O₂ (2 unpaired), NO (1 unpaired), transition metal ions (Fe²⁺, Cu²⁺, Mn²⁺). Disappears above Curie temperature for ferromagnets.

Uses & Applications

MRI contrast agents (paramagnetic Gd³⁺ complexes). Identifying unpaired electrons (ESR/EPR spectroscopy). Oxygen sensing (O₂ is paramagnetic). Magnetic susceptibility measurements for determining electron count in metal complexes. Liquid oxygen handling (paramagnetically attracted to magnets).

Safety Information

Materials with large paramagnetic susceptibility can be affected by strong magnetic fields (MRI magnets). O₂ is paramagnetic — relevant to liquid oxygen handling (fire/explosion hazard). Mn, Cu, Fe compounds: toxicity varies by compound.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Paramagnetism
Synonyms Paramagnetic material, magnetic paramagnetism, Curie paramagnetism

Frequently Asked Questions

Paramagnetism is a form of magnetism in which a material is weakly attracted to an externally applied magnetic field. It arises from unpaired electrons in atoms, ions, or molecules, which have permanent magnetic moments that align partially with an applied field. Unlike ferromagnetism, paramagnetic behavior disappears when the external field is removed and is temperature-dependent (Curie law: χ ∝ 1/T).

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