Structural and electrical properties of Na2Pb2Eu2W2Ti4X4O30 (X=Nb, Ta) ferroelectric ceramics

A new group of tungsten bronze family Na 2 Pb 2 Eu 2 W 2 Ti 4 X 4 O 30 (X = Nb, Ta) having all the valence elements (I-VI) were prepared by a high-temperature solid-state reaction technique. The formations of the compounds were confirmed by X-ray diffraction technique with an orthorhombic structure. Surface morphology of the compounds was studied by scanning electron microscope (SEM). Studies of dielectric properties ( ɛ r and tan δ ) of the above compounds at different frequencies in a wide temperature range (300–700 K) with an impedance analyzer exhibit a ferroelectric phase transition at 580 and 394 K for Na 2 Pb 2 Eu 2 W 2 Ti 4 Nb 4 O 30 and Na 2 Pb 2 Eu 2 W 2 Ti 4 Ta 4 O 30 , respectively. Ferroelectric properties of these compounds were confirmed with polarization (hysteresis) study.