Fabrication of Bi_0.5Na_0.5ZrO₃ Powder by Mixed Oxide Method

Abstract

Lead-free bismuth sodium zirconate powder with formula Na0.5Bi0.5ZrO3 was prepared by conventional mixed oxide method. Bismuth sodium zirconate (BNZ) powder with 10wt%Na2CO3 was calcined at 800 °C for 2 h dwell time. Investigation of the effects of re-calcination and dwell time on phase formation of powders was also carried out. The results revealed that re-calcination significantly affected the formation of single-phase BNZ powder. Phase characteristics were checked by X-ray diffraction (XRD). Powder Cell software was employed to simulate crystal structure of BNZ powder. It was found that BNZ powder most likely possessed an orthorhombic structure. SEM result showed its average particle size was 0.47 mm and composition measured EDX correlated with theoretical composition of BNZ.

Diffuse Dielectric Behavior of (Bi0.5Na0.5)Zr1-xTixO3Lead-Free Ceramics

“…In the ceramic without Ti addition, XRD pattern showed that BNZ ceramic possessed orthorhombic perovskite phase, in good agreement with previously reported result [2,4]. With increasing substitution, shift of diffraction pattern toward a higher reflection angle was seen due to the fact that smaller Ti 4+ ions (0.605 Å) [8] substituted larger Zr 4+ ions (0.72 Å) [8] in the lattice and then reduced the unit cell volume.…”

“…The phases were divided into three regions, the single orthorhombic phase region up to x = 0.2 mol fraction, a two-phase region at x = 0.3 and 0.4 mol fraction in which (321) orthorhombic and (300) rhombohedral peaks overlapped to cause the left side intensity (blue peak) to become higher than a right side (123 peak), then a single rhombohedral phase region beyond x = 0.5 mole fraction. The quantitative data of lattice parameters for BNZT having x = 0, 0.1, 0.2, 0.5 and 0.6 The data are taken from previous report [2]. b The data are taken from previous report [6].…”

“…This system showed a polar cluster and relaxor behavior dependent on Zr 4+ and Ti 4+ ionic ratio [1]. A few years ago, Bi 0.5 Na 0.5 ZrO 3 (BNZ) ceramic was first reported to have a negative temperature resistance behavior [2][3][4][5]. Among lead-free compounds, it was believed that this material might become a promising candidate for electronic devices such as sensor, actuator and Diffuse Dielectric Behavior of (Bi 0.5 Na 0.5 )Zr 1-x NTC thermistor.…”

Solid‐State Synthesis and Properties of Relaxor (1−x)BKT–xBNZ Ceramics

“…The unit cell of x BNZ ( x = 0–0.10) was refined using the tetragonal P 4 mm symmetry, in accordance with what is reported for BKT . The diffractograms were refined using cubic Pm m unit cell for x BNZ ( x = 0.15–0.80), while BNZ ( x = 1) was refined using the orthorhombic Pnma unit cell . At high BKT content no secondary phases could be observed by XRD, but from x = 0.2 traces of secondary phases could be observed.…”

“…A transition from rhombohedral to orthorhombic structure has been observed for BNT upon 58–60 mol% substitution of Zr for Ti . The crystal structure of Bi 0.5 Na 0.5 ZrO 3 (BNZ) has been reported to be orthorhombic Pnma …”