Effect of Particle Size on the Dielectric Properties of Sodium Potassium Niobate -Portland Cement Composites

Abstract

In this research, the effect of sodium potassium niobate, (Na_0.5K_0.5)NbO₃ (NKN) particle size on the dielectric properties of 0-3 non lead based piezoelectric cement based composites were investigated. NKN of various particle sizes (75, 225 and 450 μm) were used at 50% by volume to produce the composites. Dielectric properties at various frequencies (0.1–20 kHz) were investigated. The results showed that the dielectric values of NKN-PC composites increased with increasing NKN particle size where ε _r at 1 kHz are 158.60 and 191.21 for composites with 75 μm and 450 μm NKN particle size respectively. The dielectric loss (tanδ) was found to reduce with increasing NKN particle size and the tan δ value was lowest at 0.39 for composite with 450 μm NKN particle size.

Keywords:

• NKN
• Composites
• Particle size
• Dielectric Properties

ACKNOWLEDGMENTS

The authors are grateful to members of staff at the Electroceramics Research Laboratory for the research facilities made possible for this research work and also to the Thailand Research Fund (TRF)and the Commission on Higher Education (Thailand) for financial support.

Communicated by Dr. George W. Taylor