Structural and ferroelectric properties of perovskite Pb_(1−x)(K_0.5Sm_0.5)_xTiO₃ ceramics

Abstract

PbTiO3 has the highest tetragonal distortion (c/a ∼ 1.064) and highest spontaneous polarization among perovskite titanates.

The physical significance of imaginary phonon modes in crystals

“…As such, the form of the potential is fundamental to modelling ferroelectric and multiferroic materials. For example, the perovskite PbTiO 3 transitions from a high-temperature non-ferroelectric Pm 3m cubic phase to a ferroelectric P4mm tetragonal phase at 763 K, driven by a single zone-centre phonon mode with an associated double-well potential [30,31].…”

Structure, dielectric, and piezoelectric properties of K0.5Na0.5NbO3-based lead-free ceramics

“…The Raman spectroscopy is frequently employed to probe the subtle structural distortions induced both by the tilting of octahedra and by the cationic displacements in perovskites and other related compounds. [54][55][56][57] Fig. 3(a) shows the room temperature Raman spectra of (1 À x)KNN-(x)BZT (x ¼ 0.00 to 0.10) samples in the wavenumber range of 50-1000 cm À1 .…”

Terahertz Faraday Rotation of SrFe12O19 Hexaferrites Enhanced by Nb Doping

“…Figure a shows the frequency dependencies of the dielectric permittivity and loss tangent of the as-prepared (nonmagnetized) SFO and SFN3O samples in the THz band. The permittivity of both hexaferrites is nearly independent of the frequency due to a large ionic polarization and partly because of electronic polarization within the 0.2–0.8 THz range. A slightly higher value of ε′ and tan δ of SFN3O can be attributed to the smaller grain size effect, reduced coercive field, and higher concentration of the ferrimagnetic active regions at THz frequencies.…”