Step 1: Background:
All materials exhibit diamagnetism, a weak magnetic property where an induced magnetic field opposes the applied external field. Paramagnetic materials also possess permanent atomic magnetic dipoles that align with the external field. The total magnetic susceptibility (\(\chi\)) is the combination of paramagnetic (\(\chi_p\)) and diamagnetic (\(\chi_d\)) susceptibilities: \(\chi = \chi_p + \chi_d\).
Step 2: Explanation:
Paramagnetic susceptibility (\(\chi_p\)) is positive and inversely proportional to absolute temperature (T), described by Curie's Law (\(\chi_p \propto 1/T\)).
Diamagnetic susceptibility (\(\chi_d\)) is negative and largely temperature-independent.
For a material to exhibit net diamagnetic behavior, its total susceptibility \(\chi\) must be negative. As temperature (T) increases, paramagnetic susceptibility (\(\chi_p\)) decreases, approaching zero at high temperatures.
\[ \lim_{T \to \infty} \chi = \lim_{T \to \infty} (\chi_p + \chi_d) = 0 + \chi_d = \chi_d \]
Because \(\chi_d\) is negative, the material's magnetic response at high temperatures is dominated by its inherent diamagnetism as the paramagnetic contribution becomes insignificant. Note that the Curie temperature applies to ferromagnetic materials, not paramagnetic materials.
Step 3: Conclusion:
At sufficiently high temperatures, the paramagnetic effect becomes negligible, and the material's underlying diamagnetism dictates its magnetic behavior.