Magnetic and structural correlations in EuMnO and BiMnO crystals in the paramagnetic temperature range

The magnetic and dielectric properties of EuMn2O5 and BiMn2O5 crystals are investigated over a wide range of temperatures 4.2-250 K, including the range T much greater than T-N similar or equal to 40 K. Significant departures from the Curie-Weiss law are observed in both crystals for the magnetic susceptibility in the paramagnetic range; they are attributed to the presence of correlated domains of magnetic order over a wide range of temperatures. Anomalies in the dielectric properties of the crystals are observed in the same temperature range T>T-N and, as in the case T<T-N, are correlated with the magnetic properties. (C) 1997 American Institute of Physics.