Structural, dielectric and electrical properties of Pb5−xLa1+xTi3+xNb7−xO30 (x=0, 1 and 2) ceramics Original Research Article

The polycrystalline samples of Pb5−xLa1+xTi3+xNb7−xO30 (x=0,1,2) complex tungsten–bronze type were prepared by a high-temperature solid-state technique. X-ray diffraction (XRD) study suggests the formation of single phase compounds in an orthorhombic structure at room temperature. Detailed studies of dielectric constant (ϵ) and dielectric loss of the above compounds as a function of temperature (−150 to 350 °C) at 10 kHz exhibit a ferroelectric phase transition of diffuse type. Temperature variation of resistivity show that these compounds have negative temperature coefficient of resistance (NTCR) at high temperature.