Symmetries and multiferroic properties of novel room-temperature magnetoelectrics: Lead iron tantalate - lead zirconate titanate (PFT/PZT)

Mixing 60-70% lead zirconate titanate with 40-30% lead iron tantalate produces a single-phase, low-loss, room-temperature multiferroic with magnetoelectric coupling: (PbZr0.53Ti0.47O3)((1-x))-(PbFe0.5Ta0.5O3)(x). The present study combines x-ray scattering, magnetic and polarization hysteresis in both phases, plus a second-order dielectric divergence (to epsilon = 6000 at 475 K for 0.4 PFT; to 4000 at 520 K for 0.3 PFT) for an unambiguous assignment as a C-2v-C-4v (Pmm2-P4mm) transition. The material exhibits square saturated magnetic hysteresis loops with 0.1 emu/g at 295 K and saturation polarization P-r = 25 mu C/cm(2), which actually increases (to 40 mu C/cm(2)) in the high-T tetragonal phase, representing an exciting new room temperature oxide multiferroic to compete with BiFeO3. Additional transitions at high temperatures (cubic at T>1300 K) and low temperatures (rhombohedral or monoclinic at T<250 K) are found. These are the lowest-loss room-temperature multiferroics known, which is a great advantage for magnetoelectric devices. Copyright 2011 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License. [doi:10.1063/1.3670361]