Domain boundaries in ferroic materials are found to have various physical properties not observed in the surrounding domains. Such differences can be enhanced and bring promising functionalities when ...centrosymmetric nonpolar materials encounter polar domain boundaries. In this work, a tunable polar domain boundary is discovered in an antiferroelectric single crystal. Under a small stress or electric field, the density, volume, and polarity of the boundaries are successfully controlled.
Domain boundaries with macroscopic polarity are discovered in a nonpolar PbZrO3‐based single crystal. They can be preferentially created and erased by applying a small stress. The polarity can be enhanced or switched with a small electric field. Atomistic‐structural analysis reveals that the polar domains boundaries are formed by a combination of ↑↑↓‐like ferrielectric structures.
The second harmonic generation microscope (SHGM) constructs images of intensity distributions of SH waves produced by the interaction of fundamental waves with a polar material. We have developed ...this nonlinear optical microscope in order to make possible nondestructive, three-dimensional (3D) observations of various kinds of inorganic and organic materials. The SHGM can disclose also inverted domain structures of antiparallel spontaneous polarizations using the interference with the reference SH waves. The observation principle and several applications to structural characterizations of LiNbO3 and LiTaO3 quasi-phase matching devices, domain structure analyses of a relaxor/ferroelectric solid solution Pb(Zn1/3Nb2/3)O3-9%PbTiO3 at the morphotropic phase boundary, development of order parameter in a quantum paraelectric relaxor Li-doped KTaO3, and antiphase polar domain structures of muscle fibers and myofibrils are surveyed by stressing the high effectiveness of the SHGM as a tool of material diagnosis.
We report aerosol deposition (AD) method for preparation of bismuth layer-structured ferroelectric thick films with enhanced ferroelectric and insulating properties. Constitution phase, crystal ...structure, polarization and leakage current properties of SrBi 2 Ta 2 O 9 (SBTa) thick films with thickness of 2--4 μm were investigated. While obtained as-deposited SBTa films have slight $\mbi{c}$-axis grain orientation, the degree of orientation for the films annealed at higher than 1000 °C was the same as that for sintered bulks. Fracture cross-sectional scanning electron microscopy (SEM) images revealed that the as-deposited SBTa films on glass substrates had a fully dense microstructure. The low leakage current density ($J$) of less than $10^{-7}$ A/cm 2 at 1 MV/cm was observed for SBTa films annealed at less than 900 °C, and the SBTa films annealed at 900 °C indicated a remanent polarization ($P_{\text{r}}$) of 5.7 μC/cm 2 , which is larger than that of sintered bulks ($P_{\text{r}}$ of 4.7 μC/cm 2 ) fabricated by conventional solid-state reaction using the same starting raw powder used for the AD method.
Successive phase transitions of Pb(Zn 1/3 Nb 2/3 )O 3 --9%PbTiO 3 single crystals with the morphotropic phase boundary composition are investigated using polarization and scanning-type ...second-harmonic generation (SHG) microscopes. Clear phase transitions between monoclinic and tetragonal, and tetragonal and cubic phases are observed with temperature hysteresis. A three-dimensional domain structure with a domain boundary consistent with the $m\bar{3}mFm( p)$ transition is observed with the SHG microscope at room temperature. Monoclinic domains develop with a long relaxation time in the zero-field cooling process.
Ferroelectric BaTiO 3 and antiferromagnetic BaFeO 3 are deposited alternatively by a pulsed laser deposition method with the aim of fabricating room-temperature multiferroic materials. X-ray ...diffraction (XRD) analysis reveals that the superlattice structure is fabricated with a designed periodicity and thin film quality is improved by increasing BaFeO 3 layers. Ferroelectricity and ferromagnetic properties are examined by the double-wave method (DWM) of $D$--$E$ hysteresis loops, an XRD dilatometry, and a superconducting quantum interference device magnetometer. Our superlattice thin film shows multiferroicity, i.e., the coexistence of ferroelectricity and ferromagnetism, at room temperature.
The effect of doping metal ions in ferroelastic Pb3(PO4)2 (PPO) on the polar nature of domain boundaries (DBs) was investigated using a second harmonic generation (SHG) microscope. It has been ...already reported that (DBs) of non-doped PPO is SH active and polar. The present study reveals that DBs of Ca-doped and Mg-doped PPO show greatly enhanced SH activity. This indicates that doping by metal ions enhances the polar nature of the DBs of PPO. This is important for future applications of DB nanotechnology. The enhancement of SH intensity is explained by a larger displacement of Ca2+ and Mg2+ ions in DBs due to smaller ionic radii. Analyses of the SH anisotropy experiments reveal that the symmetry-adapted W-wall belongs to monoclinic m and the non-adapted W'-wall to monoclinic 2. Both point groups are classified as the polar classes, which coincides with the case of pure PPO.
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