Explaining the properties and functions of materials in terms of their atomic arrangements and inhomogeneous structures is a fundamental challenge for the development of ferroelectric oxides. Dielectric response, a fundamental property of matter, can be explained by long-wavelength polar lattice vibrations and dipole relaxations capable of responding to electrical bias; therefore spectroscopic methods, such as Raman spectroscopy, can be used to investigate its origin. Herein, we used angle-resolved polarized Raman mapping to investigate how phase boundaries and giant dielectric responses are related in a relaxor-Pb(Mg1/3Nb2/3)O3–ferroelectric-PbTiO3 (PMN-xPT) solid-solution system using a compositionally graded crystal, with gradual changes in polarization direction visualized by Raman mapping. The variation of the width of quasielastic light scattering with position reveals the following: The huge dielectric response observed in PMN-xPT is ascribable to the slowing down of a relaxation related to mesoscopic ferroelectric domains near the phase boundary, which is characteristic of relaxor–ferroelectric solid-solution systems and differentiates them from other ferroelectrics.

Morphotropic phase boundaries (MPBs) in relaxor Pb(Zn 1/3 Nb 2/3 )O 3 -ferroelectric PbTiO 3 systems were investigated by means of angle-resolved polarized Raman spectroscopy at 800 K in the paraelectric phase. The features of the spectra represented by contour maps were extracted through the multivariate curve resolution (MCR) method, rendering the comparison among the data with six compositions more accurate and convenient. The result indicates that the structure becomes unstable at x = 0.07, which is slightly smaller than the MPB occurring at x = 0.09. The additional analysis using the MCR method to investigate the x dependence of the extracted Raman spectra shows anomalies at the MPB. The information related to the MPB near room temperature could be extracted through Raman spectroscopy even in a simple high-temperature paraelectric phase.

Raman scattering spectroscopy was applied to characterize polycrystalline germanium (Ge) on noncrystalline substrates fabricated by solid-phase crystallization and metal-induced crystallization (MIC) using copper (Cu) and tin (Sn) as the catalyzer. The subject was focused on the material for thin-film transistors in which the precursors, with the thickness of only 15 nm, were deposited by sputtering. The optical phonon mode exhibited considerable asymmetry and was separated into the following three components: crystal, low-dimensional nanosized crystallite (NC), and amorphous. The width and frequency shift of the crystal component were analyzed using the phonon confinement effect, thermal stress, and Sn composition. The transition from amorphous to the NC state was associated with the disorder in the precursor. The addition of a restrained amount of Cu led to the evident progress of crystallization and simultaneous suppression of the NC transition. The Sn composition of 3 at% was insufficient to exhibit a noticeable MIC effect.