Antiferromagnetism in CaCu sub 3 Ti sub r O sub 12 Studied by Magnetic Raman Spectroscopy

For Ca Cu sub 3 Ti sub 4 O sub 12 - an insulator that exhibits giant dielectric response above 100 K- Cu sup 2+ antiferromagnetic spin ordering has been investigated by magnetic Raman scattering and magnetization measurements. Below the Neel temperature, T sub N = 25K, magnetic excitations have been identified. Above T sub N Raman spectra reveal short-range antiferromagnetic fluctuations that increase with cooling like T sup -1. No deviations from Curie Weiss law have been observed above T sub N.