Diffuse Phase Transition in Pb₂Sb₃DyTi₅O₁₈ Ceramic

Polycrystalline sample of Pb ₂ Sb ₃ DyTi ₅ O ₁₈ , a member of tungsten-bronze (TB) family, was prepared using a high temperature solid-state reaction technique. XRD analysis indicated the formation of a single-phase orthorhombic structure. The dielectric studies revealed the diffuse phase transition and the transition temperature found to be at 301°C. The activation energy was estimated to be 0.62 eV from the temperature variation of dc conductivity. The nature of variation of dc conductivity with temperature suggested NTCR behaviour.

Keywords:

• Pb₂Sb₃DyTi₅O₁₈
• phase transition
• dielectric constant
• orthorhombic structure

Acknowledgments

Paper originally presented at AMF-4, Bangalore, India, December 12–15, 2003