Room temperature polarization in the ferrimagnetic Ga2−xFexO3 ceramics

The effect of the Fe/Ga ratio on the magnetic and electric properties of the multiferroic Ga2−xFexO3 compound has been studied in order to determine the composition range exhibiting magnetic and electric orders coexistence and their critical temperatures. A magnetoelectric phase diagram, showing the evolution of both the Néel magnetic ordering temperature TN and the electric ordering temperature Tc, versus the iron content has been established for 0.9 ≤ x ≤ 1.4. While the ferrimagnetic Néel temperature increases with the iron content, the electric ordering temperature shows an opposite trend. The electric polarization has been found to exist far above room temperature for the x = 1.1 composition which shows the highest observed electric ordering temperature of Tc ≈ 580 K. The x = 1.3 and 1.4 compounds are ferrimagnetic-electric relaxors with both properties coexisting at room temperature.