Preparation and properties of strontium barium niobate based glass-ceramics for energy storage capacitors.

NaO-BaO-SrO-NbO-BO-SiO glass-ceramics were prepared by melt-casting followed by controlled crystallization. X-ray diffraction results show that BaSrNbO with tungsten bronze structure formed as the dielectric phases from the glass matrix at 800°C. However, a secondary phase NaSrBaNbO occurs when crystallization temperature exceeds 850°C. The glass-ceramics exhibit excellent stability in permittivity values from room temperature to 200°C and low dielectric losses below 0.05. Electrical testing demonstrates that the breakdown strength increases with crystallization temperature. The P-E characteristics at room temperature do not show any clear ferroelectric behavior. The glass-ceramic material heated at 800°C/3 h + 950°C/3 h shows a breakdown strength of 1400 kV/cm and its energy storage density can reach up to 4.0 J/cm, which may be a strong candidate for high energy density storage capacitors for portable or pulsed power applications. [ABSTRACT FROM AUTHOR]