Multiferroic orders in 0.5BiFeO3–0.5Bi0·5K0·5TiO3

Abstract

Abstract We report our studies on the multiferroic orders in 0.5BiFeO3–0.5Bi0·5K0·5TiO3 (0.5BF–0.5BT) in this paper. The XRD pattern in the powdered form suggests a pseudocubic phase on average, with a lattice parameter of ∼3.9572 A. However, the bulk sample shows a coexistence of pseudocubic and tetragonal phases. The dielectric anomaly is relaxor-like, with the Burns temperature (TB) of ∼760 K. The remnant polarization (Pr, 4.02–4.25 μC/cm2) is nearly unchanged in the temperature range of 298 K and 398 K. In addition, the normalized strain coefficient (d × 33) increases on heating, from 100 pm/V at 298 K up to 240 pm/V at 453 K. On the other side, two anomalies were confirmed in the temperature dependence of the magnetic susceptibilities. The high-temperature anomaly is related to a transition between the antiferromagnetic and paramagnetic states around ∼143 K. The low-temperature anomaly around ∼5.5 K might hint the onset of the magnetic spin glass state. We believe that some common features should be present in (BixA1-x) (Fe0·5B0.5)O3 (A cations are not ferroelectric active while B cations are not magnetic active).