Difficulty: Easy
Correct Answer: becomes a paramagnetic material
Explanation:
Introduction / Context:
The Curie temperature marks a phase transition in ferromagnets where spontaneous magnetization vanishes due to thermal agitation overpowering exchange interactions.
Given Data / Assumptions:
Concept / Approach:
Below Curie temperature, spins align spontaneously, yielding strong magnetization. Above it, long-range order is destroyed and the material behaves as a paramagnet obeying Curie–Weiss law with χ ∝ 1/(T − θ).
Step-by-Step Solution:
Increase T beyond Curie temperature.Spontaneous magnetization M_s → 0.Response to applied field becomes paramagnetic.Thus, choose “becomes a paramagnetic material”.
Verification / Alternative check:
Magnetization–temperature curves for iron or nickel show sharp drop at Curie point, followed by weak paramagnetic behavior.
Why Other Options Are Wrong:
Ferromagnetism does not strengthen with heat; diamagnetism is weak and not the generic high-temperature phase; “none” and “antiferromagnetic” do not match the established transition.
Common Pitfalls:
Confusing Néel temperature (antiferromagnets) with Curie temperature (ferromagnets).
Final Answer:
becomes a paramagnetic material
Discussion & Comments