High temperature properties of multiferroic BiFeO3-DyFeO3-BaTiO3 solid solutions

Dielectric and magnetic properties of the xBiFeO3-yDyFeO3-zBaTiO3 solid solution ceramics at high temperature range of RT ∼600 °C have been characterized. For the more detailed understandings of the multiferroic property, the relation between the crystal structure transition, magnetic transition, dielectric transition with increasing temperature have been analyzed. Residual magnetization Mr under the low and high applied magnetic fields (H = 20 Oe, 8 kOe) and the dielectric properties, ɛr and tan δ, with varying measuring frequency and temperature have been characterized using the vibrating sample magnetometer and LCR meter, respectively. The neutron diffraction data has been collected at the temperature range of RT ∼800 °C. The low DyFeO3 concentration samples (y = 0, 0.025) show the magnetic transitions at temperature range of 410-430 °C, while the high DyFeO3 samples (y ≥ 0.05) show the additional transition at 250-290 °C. The magnetic transition at 410-430 °C corresponds to the crystal structural transition to the tetragonal P4mm from the rhombohedral R-3c, at which the BiFeO3 and the DyFeO3 samples lose their antiferromagnetic ordering.