Stress dependence of the Raman spectrum of polycrystalline barium titanate in presence of localized domain texture

Abstract

The stress dependence of the Raman spectrum of polycrystalline barium titanate (BaTiO3, BT) ceramics has been examined with microprobe polarized Raman spectroscopy. The angular dependence of the Raman spectrum of the tetragonal BT crystal has been theoretically established, enabling us to assess the stress dependence of selected spectral modes without the influence of crystallographic domain orientation. Upon considering the frequency shift of selected Raman modes as a function of orientation between the crystallographic axis and the polarization vector of incident and scattered light, a suitable instrumental configuration has been selected, which allowed a direct residual stress measurement according to a modified piezospectroscopic procedure. The analysis is based on the selection of mixed photostimulated spectral modes in two perpendicular angular orientations.

Influence of ZrO_2 Addition on the Structure and Dielectric Properties of BaTiO_3 Ceramics

“…Peaks 302, 512, and 712 cm −1 are found in all ferroelectric phases of BT-based materials. Peaks 280 cm −1 and 512 cm −1 have a dominant A 1 (TO) character, as was proven in polycrystalline BT by polarization measurements [14,15], and the former is associated with polar Ti-O vibrations. …”

Probing structural changes in Ca(1−x)Nd2x/3TiO3 ceramics by Raman spectroscopy

“…A more complex behavior characterizes the modes of B g species, for which generally a periodicity of p/2, instead of p, is expected. 38,39 This, however, applies to single-crystalline materials, whereas in polycrystals the overall response is a function of the domain distribution. The more the ensemble of microscopic domains is oriented in one preferential direction, the more the intensity response can be approximated to that of a single crystal.…”

Raman tensor elements for tetragonal BaTiO3 and their use for in-plane domain texture assessments

“…Direct observation of domain textures has been mainly made in BT using polarized optical microscopes; 1-3 accordingly, the details of domain switching could be clarified by separating contributions to the switching current from domain nucleation and domain wall motion under different field strengths. In three recent papers, [18][19][20] we have examined in detail and with renewed interest some aspects of polarized Raman spectroscopy in ferroelastic materials, with the main aim of separating the effect on Raman emission of applied/ residual stress fields from that of the internal development of a domain texture. 6-8͒ and the interrelationship between the anomalous electromechanical, structural, and thermal properties of BT phenomenologically modeled.…”