EFFECT OF SINTERING TEMPERATURE AND TIME ON STRUCTURAL AND DIELECTRIC PROPERTIES OF TB-DOPED BATIO₃ CERAMICS

Dayong Lu, Xianglu Gao, Yuchun Fu

ABSTRACT:Ba1−x/2Ti1−x/2TbxO3 (x = 0.05) ceramics (BTTb5) were prepared at Ts = 1400 °C for t = 6‒24 h and at Ts = 1300‒1480 °C for t = 24 h using the cold-pressing ceramic processing technique. All of BTTb5 ceramics satisfy EIA X5R dielectric specification and exhibit a tetragonal perovskite structure. The sintering temperature and the sintering time have little influence on the crystal structure and dielectric properties of BTTb5. The optimum preparation condition of BTTb5 is determined as Ts = 1400 °C for t = 12 h because of higher relative density (ρr = 94 %) and lower dielectric loss (tan δ = 0.0108). As the sintering time increases, the XRD and EPR results reveal that more B-site Tb4+ ions are reduced to A-site Tb3+. The higher sintering temperature is apt to ceramic densification and the incorporation of more Tb4+ ions into B-sites.

Keywords:Tb-doped BaTiO3 ceramics, X-ray diffraction, mixed-valent state, dielectric properties, electron paramagnetic resonance.