FENG Xianjie ¹, CHEN Guohua ^{1, 2}
(1. School of Material Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, Guangxi, China; 2. Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology, Guilin 541004, Guangxi, China)

Abstract: (33.5+x) Na₂O-33.5Nb₂O₅-33B₂O₃ (Abbreviated as NN, x=0, 2, 4, 6) glass-ceramics were fabricated using the conventional high-temperature melting technique followed by a controlled crystallization process. The impact of varying x values on the phase composition, microstructure, ferroelectric characteristics, and energy storage capabilities of boro-niobate glass-ceramics was comprehensively investigated. The findings reveal that the predominant crystal phase of all boro-niobate glass-ceramic samples is NaNbO₃ with perovskite structure. When x is less than 4, the second phase Na₂Nb₄O₁₁ appears concomitantly in the glass-ceramics. With the increase of x value, the structure of NaNbO₃ antiferroelectric P phase changes to ferroelectric Q phase. All boro-niobate glass-ceramics exhibit obvious ferroelectric characteristics. When x=4, the dielectric constant of the glass-ceramic sample reaches 153, and a higher breakdown strength of 1205.81 kV·cm⁻¹ is obtained, and the recoverable energy storage density (Wrec)of 0.81 J·cm⁻³ when 800 kV·cm⁻¹ field strength was applied, the instantaneous discharge power density (Wd) at 600 kV·cm⁻¹ field strength is 145.87 MW·cm⁻³. The boro-niobate system glass ceramics are expected to be used in pulse power systems.
Key words: sodium niobate; glass-ceramics; energy storage density; breakdown strength