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The electric field (E) controlled magnetism in the multiferroic heterostructure comprising polycrystalline yttrium iron garnet (YIG) film, Pt electrodes, and lead magnesium niobate-lead zirconate titanate (PMN-PZT) ceramic is presented in this work. The electric-field-dependent magnetization and susceptibility of YIG film reveal the strain-mediated transformation of magnetocrystalline anisotropy. A strong converse magnetoelectric (CME) effect has been observed in the YIG/Pt/PMN-PZT/Pt heterostructure, and the CME coefficient can reach 17 × 10−8 s/m at 0 Oe and 4.2 kV/cm. The reversible magnetization switching by means of a low voltage pulse (±4.6 kV/cm) can be realized at 0 Oe in the YIG/Pt/PMN-PZT/Pt heterostructure, and the E-tunable susceptibility can reach Δχ/χ0+ = 55.5% at 20 Oe and 4 kV/cm. These results show great potential in power-efficient magnetoelectric components for information storage and tunable devices. [ABSTRACT FROM AUTHOR]

The artificial multiferroic heterostructure used in this work is composed by an yttrium iron garnet (YIG) film deposited by radio frequency (rf) magnetron sputtering on a metalized PMN-PZT ceramic. We demonstrate, thanks to the well-known converse magnetoelectric (CME) coupling, the control of the magnetic state of the YIG film by means of a low electric field applied to the PMN-PZT ceramic. In particular, it is shown that the variations of the magnetization induced by the strain are functions of the magnetic sate of the film. It is shown that the maximum amplitude variation is observed at the coercive magnetic field (Hc), whereas when H increases, the strain effect has a limited impact on the film magnetization. A second effect has also been remarked on the magnetization of the YIG film but only after the first strain induced cycle has been applied. These variations, observed only under low applied magnetic fields, can be attributed to the re-orientation of some magnetic moments which are easy to switch under low magnetic fields. We find that after poling the YIG film, i.e., applying a magnetic field on it, the initial state is restored. The CME coupling coefficient is determined for different magnetic states of the YIG film, and the maximum value 11 × 10−8 s/m is obtained at H = Hc and E = Ec (the coercive field of the PMN-PZT ceramic). The relative susceptibility tunability available for the heterostructure proposed is 16.8% for an electric field applied between 0 and −4 kV/cm. [ABSTRACT FROM AUTHOR]

We report the electric-field-induced ferroelectric (FEIN) to antiferroelectric (AFE) phase transition that is tuned by the poling temperatures in 0.89Bi0.5Na0.5TiO3-0.06BaTiO3-0.05K0.5Na0.5NbO3 (0.89BNT-0.06BT-0.05KNN) ceramics. Phase transition and pyroelectric behaviors of the ceramics were investigated as functions of temperature and electric field. Pyroelectric coefficient peaks of (3 ∼ 6.5) × 10-8 C cm-2 K-1 are detected at about 10 °C above the poling temperatures for the samples poled at different temperatures. The poling temperature tuned pyroelectric behaviors are attributed to the FEIN to AFE phase transition when the temperature increases. [ABSTRACT FROM AUTHOR]

The electric field dependence on the dielectric properties of the porous ceramics was studied theoretically. The dielectric constant of the porous ceramics under certain direct current (dc) bias field and the real strength electric field in the porous ceramics were given quantitatively. As the pore can share the electric field, the tunability of the porous ceramics will be decreased when the porosity increases. The dielectric constant evolution of Ba0.6Sr0.4TiO3-based porous ceramics with the dc bias electric field can be successfully explained by our theoretical results. Taking Ba0.6Sr0.4TiO3-based porous ceramic samples, for example, there is good correspondence between the theoretical and the experimental results. [ABSTRACT FROM AUTHOR]

The ferroelectric hysteresis loops of 63PbTiO3-37BiScO3 ceramics were measured under sinusoidal electric fields in the range of frequency from 0.1 to 100 Hz and field from 5 to 55 kV/cm. The fitting results showed two linear relations existed between the logarithm of hysteresis area and the logarithm of the amplitude of field E0 in the first and third field region. In the second region, no linear relation existed due to polarization reversal. These three-stage behaviors were distinct from the existing two-stage behaviors. The slopes in the third stage increase with the increasing of frequency, which can be attributed to dielectric loss under high frequency. [ABSTRACT FROM AUTHOR]