Precursor Phenomena of Barium Titanate Single Crystals Grown Using a Solid-State Single Crystal Growth Method Studied with Inelastic Brillouin Light Scattering and Birefringence Measurements.

Soo Han Oh,Ho-Yong Lee,Iwona Lazar,Krystian Roleder,Jae-Hyeon Ko

doi:10.3390/molecules23123171

Abstract

The nature of precursor phenomena in the paraelectric phase of ferroelectrics is one of the main questions to be resolved from a fundamental point of view. Barium titanate (BaTiO3) is one of the most representative perovskite-structured ferroelectrics intensively studied until now. The pretransitional behavior of BaTiO3 single crystal grown using a solid-state crystal growth (SSCG) method was investigated for the first time and compared to previous results. There is no melting process in the SSCG method, thus the crystal grown using a SSCG method have inherent higher levels of impurity and defect concentrations, which is a good candidate for investigating the effect of crystal quality on the precursor phenomena. The acoustic, dielectric, and piezoelectric properties, as well as birefringence, of the SSCG-grown BaTiO3 were examined over a wide temperature range. Especially, the acoustic phonon behavior was investigated in terms of Brillouin spectroscopy, which is a complementary technique to Raman spectroscopy. The obtained precursor anomalies of the SSCG-grown BaTiO3 in the cubic phase were similar to those of other single crystals, in particular, of high-quality single crystal grown by top-seeded solution growth method. These results clearly indicate that the observed precursor phenomena are common and intrinsic effect irrespective of the crystal quality.

Highlights

IntroductionFerroelectric materials have been adopted in a wide range of applications, such as capacitors, memories, and piezoelectric devices
Ferroelectricity is defined in terms of the appearance of the spontaneous polarization under a certain thermodynamic condition, which can be switched by applying an external electric field
We focus on the precursor phenomena of BaTiO3 single crystals grown using a solid-state single crystal growth (SSCG) method [41,42] and compare the results with those of our previous results on BaTiO3 single crystals grown using a top-seeded solution growth (TSSG)

Summary

Introduction

Ferroelectric materials have been adopted in a wide range of applications, such as capacitors, memories, and piezoelectric devices. Perovskite-based oxide materials have attracted much attention due to their superior ferroelectric and electromechanical properties, and high potential in their applications. They are promising materials from the viewpoint of fundamental physics because of their rich structural and dynamical properties during the ferroelectric phase transition [1,2]. Barium titanate (BaTiO3 ) is one of the most well-known ferroelectrics, where the molecular unit. BaTiO3 comprises the primitive unit cell in the paraelectric cubic phase.

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Conclusion