Paramagnetism – Nature of Magnetic Dipoles and Interactions Paramagnetic materials possess permanent magnetic dipoles, but the interaction between neighboring dipoles is negligible. Is this statement correct?

Introduction / Context:
Magnetic behavior of solids spans diamagnetism, paramagnetism, ferromagnetism, antiferromagnetism, and ferrimagnetism. Paramagnetic materials are characterized by atomic or ionic moments that tend to align weakly with an external magnetic field but do not exhibit spontaneous magnetization when the field is removed. This question checks whether you recognize the role of permanent dipoles and their weak mutual interactions in paramagnets.

Given Data / Assumptions:

• Presence of unpaired electrons in atoms/ions leading to nonzero magnetic moments.
• Thermal agitation at ordinary temperatures is significant.
• No strong exchange interactions like those found in ferro- or antiferromagnets.

Concept / Approach:

In paramagnets, each ion or atom has a permanent magnetic moment (from spin and/or orbital angular momentum). However, the exchange interaction between neighboring moments is negligible, so these dipoles are randomly oriented at zero field due to thermal fluctuations. When an external field is applied, a slight statistical bias toward alignment appears, producing a small positive susceptibility that follows Curie or Curie–Weiss law (χ ∝ 1/T or 1/(T − θ)). Removal of the field returns the system to random orientation, hence no hysteresis or remanence.

Step-by-Step Solution:

Verification / Alternative check:

Measured susceptibilities for typical paramagnets (e.g., Al, Mn salts) are small (χ ≪ 1) and temperature dependent per Curie-type laws, consistent with independent-dipole behavior.

Why Other Options Are Wrong:

• False: would suggest no permanent dipoles or strong interactions, inconsistent with paramagnetism.
• Depends only on temperature: while temperature matters, the negligible interaction definition remains valid across temperatures where no ordering transition occurs.
• True only in external field: dipoles exist even without a field; the field merely biases their orientation.

Common Pitfalls:

Confusing paramagnetism with ferromagnetism (strong interactions and spontaneous order) or diamagnetism (no permanent dipoles; induced moments oppose the field).

Final Answer:

True