Magnetic study of CMR perovskite manganite (Pr,Ca)MnO3−δ: spin-flop in antiferromagnetic state and anomalous microwave response with the charge ordering Original Research Article

The magnetization and the microwave response of (Pr,Ca)MnO3−δ were measured in the temperature range from 4.2 to 270 K under the magnetic field up to 14 T. A small magnetization jump due to the spin-flop was newly observed below TN. Temperature dependence of the spin-flop field was analyzed with the two-sublattice model. The antiferromagnetic exchange field, HE=18.5 T was obtained. The microwave response at 34 GHz showed large anomalies with charge ordering, which may be related to not only resistive change but also dielectric change due to charge redistribution.