Pyroelectric and dielectric properties of lead-free ferroelectric Ba3Nb2O8 ceramic

• Barium orthoniobate (lead-free perovskite) crystallizes as palmierite with structural stability.
• The material exhibits ferroelectric phase transition of diffuse-type suitable for devices.
• The low values of εr and tan δ at high frequencies makes it a potential candidate for microwave applications.
• The material has very good pyroelectric properties for detector application.
• The material exhibits smaller value of dc activation energy.

The present study highlights ferroelectric phase transition, dielectric, pyroelectric properties and conduction mechanism of highly crystallized barium orthoniobate (Ba3Nb2O8) ceramic, prepared by a solid-state reaction technique. X-ray diffraction studies show the formation of a single-phase compound in hexagonal crystal system. Detailed studies of dielectric parameters (εr and tan δ) of the compound as a function of temperature and frequency reveal their independence over a wide range of temperature and frequency. An anomaly in εr suggests the possible existence of a ferroelectric–paraelectric phase transition of diffuse-type in the material. The low dielectric loss and moderate relative permittivity make this material (with certain modification) a potential candidate for microwave applications. Studies of pyroelectric properties reveal that the materials have reasonably high figure of merit useful for fabrication of pyroelectric detectors. The low-leakage current and negative temperature coefficient of resistance (NTCR) behavior of the sample have been verified from J–E plots. The nature of variation of dc conductivity with temperature confirms the Arrhenius and NTCR behavior of the material.

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