COMPLEX IMPEDANCE SPECTROSCOPY ON ZnO-B₂O₃ DOPED (Ba, Sr)TiO₃ CERAMICS

Abstract

BST ceramics with doping of 1, 3, and 5 wt.% ZnBO were prepared by the conventional mixed oxide method and sintered at 1100°. X-ray diffraction analyses were carried out to verify the structural properties. 1, 3, and 5 wt.% ZnBO doped BST ceramics were crystallized with weak tetragonal structure at 1100°C. The grain growth behavior and shapes were investigated by scanning electron microscopy images. The electrical properties of 1, 3, and 5 wt.% ZnBO doped BST ceramics were investigated by impedance spectroscopy at the different temperatures (350, 375, and 400°C). Impedance spectroscopy data presented in Nyquist plot show the existence of both grain and grain boundary effects in all specimens. 1, 3, and 5 wt.% ZnBO doped BST ceramics showed negative temperature coefficient of resistance (NTCR). Also, the capacitances and resistances of grains and grain boundaries for 1, 3, and 5 wt.% doped BST ceramics were simulated through equivalent circuit with the parallelly connected capacitors and resistors. The capacitance and resistance were decreased when temperature and ZnBO dopants were increased.

Structural, dielectric and electrical properties of Zn doped Ba0.8Sr0.2TiO3

“…Due to its high dielectric constant, such material is not suitable for other applications in microelectronic field. The improvement of ferroelectric and dielectric properties of BST is related to several parameters such as grain size porosity, additive concentrations [1,[7][8], sintering conditions [8][9] and oxide doping [10][11]. Recently, several research groups have examined the role played by the addition of different oxides.…”