The nature of magnetoelectric (ME) interactions has been investigated in lead zirconate titanate (PZT) and (111) or (110) single-crystal nickel zinc ferrites. Data on the dependence of low-frequency ME voltage coefficients on static magnetic field orientation show (i) highest ME coefficients for bias field H along [100] and the smallest for H parallel to [110] and (ii) strongest ME interactions for transverse fields and for samples with Zn concentration of 0.3. Measurements on frequency dependence of ME coefficients reveal resonance enhancement due to bending and radial acoustic modes. The highest voltage coefficient is measured for radial modes in a sample with Zn concentration of 0.2. Theoretical estimates of low-frequency and resonance ME parameters are in very good agreement with data.
A liquid-precursor process was used to produce an epitaxial all-oxide ferroelectric memory device structure. The lanthanum strontium manganate–lead zirconate titanate–lanthanum strontium manganate (LSMO–PZT–LSMO) structure used for this device shows excellent polarization and fatigue behavior with a remnant polarization Pr of 42 µC/cm2 and a coercive field Ec of 68 keV. The polarization was found to only slightly degrade after over 1010 fatigue cycles. This behavior is contrasted with epitaxial PZT using a metal top electrode. In addition, the use of a top LSMO electrode was a sufficient barrier to Pb loss during heating to allow subsequent (or prolonged) heat treatments that would generally lead to Pb loss.
Phase transitions in Zr-rich lead zirconate-titanate studied by single-crystal diffuse and inelastic X-ray scattering