Optical transmittance and energy storage properties of potassium sodium niobate glass-ceramics.

In this work, 0.8(K 2 O-Na 2 O-2Nb 2 O 5)−0.2((1- x)B 2 O 3 - x P 2 O 5) (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) glass-ceramics have been fabricated. The effects of P 2 O 5 on the microstructure and properties of the glass-ceramics were comprehensively studied. The addition of P 2 O 5 promotes the transition of the glass network structure from a negatively charged [B∅ 4 ]- tetrahedron to an electrically neutral [BP∅ 4 ] tetrahedron. With the increase of P 2 O 5 content, the formation of K 2 B 4 O 7 is inhibited, with major phase of Na 0.9 K 0.1 NbO 3 and minor phase of K 2 B 4 O 7. It is found that the band gap width of the glass-ceramics increases from 3.34 eV to 3.52 eV firstly and then decreases to 3.43 eV. The grain size of the glass-ceramics decreases from 150 nm to 50 nm. High optical transmittance (63%), large discharge energy density (4.58 J/cm3) and large energy storage efficiency (98%) have been simultaneously obtained for K 2 O-Na 2 O-Nb 2 O 5 -B 2 O 3 -P 2 O 5 glass-ceramics, which are potential for the applications of the transparent pulse capacitors. [ABSTRACT FROM AUTHOR]