The magnetic and dielectric properties of ferroelectromagnet (FEM) ${\mathrm{Pb}(\mathrm{Fe}}_{1∕2}{\mathrm{Nb}}_{1∕2}{)\mathrm{O}}_3$ (PFN) single crystals have been investigated. Anomalies in the dielectric constant as a function of temperature have been observed near its Néel temperature of $\sim 143\mathrm{K}$, which are indicative of the so-called magnetoelectric coupling between the ferroelectric and antiferromagnetic orders in this compound. The results coincide with previous theoretical predications. It is demonstrated that a weak magnetic transition appeared at a temperature a little below the Néel temperature, confirming the earlier prediction from the Monte Carlo simulation in a qualitative sense. The magnetic hysteresis measurement proves that there does exist weak magnetic order in PFN crystal below its Néel temperature. The Mössbauer spectra also support the existence of the magnetic order.

• Received 23 December 2003

DOI:https://doi.org/10.1103/PhysRevB.70.132101