Synthesis, phase transformation and dielectric properties of sol–gel derived Bi2Ti2O7 ceramics

Abstract

Sol-gel derived Bi 2 Ti 2 O 7 ceramic powders have been prepared from methoxyethoxides of bismuth and titanium (molar ratio of Ti/Bi = 1.23 and water/alkoxides = 1.31). The Bi 2 Ti 2 O 7 phase was stable at a low temperature (700 • C), but it then transformed into mixed phases of Bi 4 Ti

Phase structure and electric properties of Bi0.5(Na0.825K0.175)0.5TiO3 ceramics prepared by a sol–gel method

“…3, an impurity phase was formed at 550 • C. The diffraction peaks can be assigned to Bi 2 Ti 2 O 7 structure as reported in the ICPDS File No. 32-0118 [17,18]. When the temperature rised to 700 • C, the diffraction peaks belonging to Bi 2 Ti 2 O 7 disappeared, only diffractions belonging to pure perovskite phase were observed, and there is no evidence of a second phase at 700 • C and above.…”

Synthesis and characterization of lead-free K0.5Bi0.5TiO3 ferroelectrics by sol–gel technique

“…It was found that the amorphous dried gel was transformed into cubic pyrochlore Bi 2 Ti 2 O 7 (JCPDS file NO. 32-0118) in the temperature region between 500 and 600 1C [11,12]. Further increasing temperature above 600 1C, the characteristic peaks of KBT crystals appeared and at 700 1C, only pure KBT phase (JCPDS file NO.…”

Effect of La doping on structural and electrical properties of Bi2Ti2O7thin films

“…The d values of the peaks agree very well with those given in JCPDS data cards for Bi 4 Ti 3 O 12 . The phenomenon of transformation between pyrochlore phase and perovskite phase has been found in many reports [14,22,23], indicating that perovskite phase is a more thermodynamically favored phase than pyrochlore phase.…”