Antiferromagnetism in CaCu3Ti4O12 studied by magnetic Raman spectroscopy

For CaCu3Ti4O12—an insulator that exhibits a giant dielectric response above 100 K—Cu21 antiferromagnetic spin ordering has been investigated by magnetic Raman scattering and magnetization measurements. Below the Ne´el temperature, TN525 K, magnetic excitations have been identified. Above TN Raman spectra reveal short-range antiferromagnetic fluctuations that increase with cooling like T21. No deviations from Curie-Weiss law have been observed above TN .