1. Symmetries and multiferroic properties of novel room-temperature
magnetoelectrics: Lead iron tantalate –lead zirconate titanate
(PFT/PZT) by: Dilsom A. Sanchez, N. Ortega, A. Kumar, R. Roque-
Malherbe, R. Polanco, J. F. Scott, and Ram S. Katiyar
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 C2v-
C4v (Pmm2-P4mm) transition. The material exhibits square
saturated magnetic hysteresis loops with 0.1 emu/g at 295 K
and saturation polarization Pr =25 μC/cm2, which actually
increases (to 40 μC/cm2) 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.
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