Growth of lead-free piezoelectric 0.45BZT–0.55BCT single crystal and investigation of dielectric, polarization and birefringence properties

• Published in: Journal of crystal growth 2013-07, Vol.375, p.20-25
• Main Authors: Bhaumik, Indranil, Singh, Gurvinderjit, Ganesamoorthy, S., Bhatt, R., Karnal, A.K., Tiwari, V.S., Gupta, P.K.
• Format: Article
• Language: English
• Subjects: A1. Polarized light microscopy; A2. Single crystal growth; Anomalies; B1. Perovskites; B2. Ferroelectric materials; B2. Lead-free piezoelectric materials; Birefringence; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Crystal growth; Crystalline state (including molecular motions in solids); Crystals; Dielectric constant; Dielectric, piezoelectric, ferroelectric and antiferroelectric materials; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Ferroelectric phase transition; General studies of phase transitions; Materials science; Methods of crystal growth; physics of crystal growth; Nucleation; Physics; Polarization; Single crystals; Structure of solids and liquids; crystallography; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; Theory of crystal structure, crystal symmetry; calculations and modeling
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2013.04.033

Single crystals of 0.45BZT–0.55BCT were grown by spontaneous nucleation technique. The X-ray diffraction shows that grown crystals possess tetragonal symmetry with c/a=1.009. The dielectric constant shows anomalies near 109°C and 2°C corresponding to cubic-to-tetragonal and tetragonal-to-rhombohedral phase transitions, respectively. In addition, an abrupt non-dispersive decrease in dielectric constant was observed near 103°C. Temperature dependent birefringence and remnant polarization measurement also show a sharp decrease near 103°C. This anomaly in dielectric, birefringence and polarization measurements is attributed to the formation of macro-domains below 103°C. Investigation under optical microscope showed that the crystals have optical birefringence ∼0.051 and are negative uniaxial at room temperature. •Single crystals of 0.45BCT–0.55 BZT are grown by spontaneous nucleation.•Temperature dependent birefringence of the material is reported for the first time.•In-situ observation of phase transition by polarized light microscope carried out.•Anomaly in dielectric, birefringence and polarization measurements is observed.•It is attributed to the formation of macro-domains below 103°C.