Effects of Mn and Sr Doping on the Electrical Properties of Lead-Free 0.92BCZT-0.08BZT Ceramics

Abstract

The effects of Mn and Sr doping on the electrical properties of lead-free 0.92[(Ba_0.85Ca_0.15Zr_0.1Ti_0.9)O₃]-0.08[(BiZn_0.5Ti_0.5)O₃] ceramics have been studied. A-site and B-site doping with 0.00–0.05 mol% of SrCO₃ and 0–0.25 mol% of MnO₂ was performed. The ceramics were prepared using the solid state reaction technique. The powder was ball-milled for 24 h, then calcined at 1,000ºC for 4 h and sintering at 1,300ºC for 2 h. Phase formation and microstructure of ceramics were examined using an x-ray diffractometer (XRD) and scanning electron microscopy (SEM). All samples have a single phase of perovskite structure. Grain size and density value were in the range of 3.43–4.07μm and 5.78–5.83 g/cm³, respectively. The electrical properties of the ceramics were investigated as a function of Mn and Sr doping. It was found that the dielectric constant, activation energy and ac conductivity change with the dopant. Moreover, Mn and Sr doping lead to a decrease of dielectric loss, lower than 0.003 for all samples (at 1 kHz).

Keywords:

• Lead Free Ceramics
• Phase Formations
• Solid State Reaction
• Dielectric Properties
• Perovskite Structure

Acknowledgments

The authors would like to express their sincere gratitude to the Thailand Research Fund (TRF) the Royal Golden Jubilee Ph.D. program, the Graduate School and Faculty of Science, Chiang Mai University and Mae Fah Luang University, Thailand for their financial support. We wish to thank the National Research University (NRU) Project under Thailand's Office of the Higher Education Commission for financial support.