Antiferromagnetism in CaCu₃Ti₄O₁₂ studied by magnetic Raman spectroscopy

For CaCu$_{3}$Ti$_{4}$O$_{12}$ -- an insulator that exhibits a giant dielectric response above 100 K -- Cu$^{2+}$ antiferromagnetic spin ordering has been investigated by magnetic Raman scattering and magnetization measurements. Below the N\'eel temperature, T$_{N} = 25$ K, magnetic excitations have been identified. Above T$_{N}$ Raman spectra reveal short-range antiferromagnetic fluctuations that increase with cooling like T$^{-1}$. No deviations from Curie-Weiss law have been observed above T$_{N}$.