Magnetic properties of PbFe1/2Nb1/2O3: Mossbauer spectroscopy and first-principles calculations

Magnetic properties of magnetoelectric PbFe1/2Nb1/2O3 (PFN) have been studied with the help of Mossbauer spectroscopy. In contrast to the belief that Nb and Fe are randomly distributed in the lattice, we found that the Fe ions occupy two crystallographic positions, which differ by the quadrupole splitting and magnetic field mirroring the difference in the nearest neighbor environment of the Fe ions. The ratio of the weights of these positions is 2.3, at 14 K. First-principles calculations provide a microscopic insight of this finding.