2009/04/15 by Yuji Hiruma, Hajime Nagata, Tadashi Takenaka · 443 citations
Chemistry · Engineering · Materials Science · #Acoustic Wave Resonator Technologies #Analytical Chemistry (journal) #Annealing (glass) #Atmospheric temperature range #Bismuth #Bismuth titanate #Ceramic #Chemistry #Composite material #Condensed matter physics #Dielectric #Ferroelectric and Piezoelectric Materials #Ferroelectricity #Materials science #Metallurgy #Microwave Dielectric Ceramics Synthesis #Mineralogy #Optoelectronics #Phase (matter) #Phase transition #Piezoelectricity #Sintering #Tetragonal crystal system #Thermodynamics
paper · doi:10.1063/1.3115409
published in Journal of Applied Physics 105(8) (American Institute of Physics)
openalex publication_date 2009/04/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Stoichiometric and nonstoichiometric (Bi0.5Na0.5)TiO3 (BNT) ceramics were prepared by a conventional ceramic fabrication process. This study revealed that the high conductivity of BNT ceramics is associated with Bi vaporization during sintering. An x-ray study revealed that a tetragonal phase exists in the temperature range between 330 and 480 °C in BNT ceramic as well as BNT single crystals. In addition, the depolarization temperature Td, rhombohedral-tetragonal phase transition temperature TR-T, and the temperature Tm of the maximum dielectric constant were determined to be 187, approximately 300, and 325 °C, respectively, from the temperature dependences of dielectric properties using unpoled and poled specimens. The piezoelectric properties of all vibration modes and the temperature dependences of the piezoelectric properties were measured using fully poled BNT ceramics. It was also revealed that BNT ceramics exhibit three thermal depoling processes at Td, between Td and TR-T, and between TR-T and Tm from the effects of annealing on the field-induced strain, x-ray diffraction patterns, and dielectric constant of poled specimens.