  During the last fifteen years, multiferroic (MF) research communities have
been searching for an alternative room temperature MF material with large
magnetoelectric (ME) coupling for possible applications in high density
electronic components, low heat dissipation memory and logic devices. We have
studied Pb(Zr0.20Ti0.80)0.70Pd0.30O3-{\delta} (PZTP30) system with an unusually
large (30%) palladium occupancy in B site of PZT. This material exhibited a
giant ME coupling coefficient ~0.36 mV/cm.Oe. Interestingly, this is the first
time any room temperature single phase compound that showed ME trends, and
magnitude similar to those in the well established mechanical strain-mediated
ferroelectric and ferromagnetic composites; the latter ones are already in the
commercial stage as nT/pT magnetic field sensors due to their large ME values.
The presence of Pd in PZTP30 has been confirmed by XPS and XRF studies and
assigned with related binding energies of Pd+2 and Pd+4 ions as 336.37 eV,
342.9 eV, and 337.53 eV, 343.43 eV, respectively, which may be the origin of
room temperature magnetism in Pd substituted PZT ceramics. A sharp first order
ferroelectric phase transition was observed at ~569 K (+/-5 K) that is
confirmed from dielectric, Raman, and thermal analysis. Both ferromagnetic and
ferroelectric orderings with large ME coupling were found above room
temperature, a significant step forward in the development of single phase ME
material with enhanced functionalities.
