Investigation Of Density Of States And Electrical Properties Of Chemically Synthesized Ba0.5Co0.5Bi2NbTaO9 Nanoceramics

¹Department of Chemistry, Sidho-Kanho-Birsha University, Purulia 723101, India

²Centre for Materials Science and Nanotechnology, Department of Chemistry, University of Oslo, Blindern, N-0315 Oslo, Norway

³Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India

⁴Department of Biological Sciences, Presidency University, Kolkata 700073, India

Adv. Mater. Lett., 2016, 7 (11), pp 852-860

DOI: 10.5185/amlett.2016.6203

Publication Date (Web): Oct 01, 2016

Copyright © IAAM-VBRI Press

E-mail:debasisdhak@yahoo.co.in, prasanta.dhak@smn.uio.no

Abstract

In this present work, nanocrystalline Co²⁺ and Ta⁵⁺ substituted barium bismuth niobate Ba_0.5Co_0.5Bi₂NbTaO₉ was synthesized by chemical process. Room temperature single phase, tetragonal structure was confirmed using X-ray diffraction (XRD) study. Average crystallite and particle sizes were found to be 33 nm and 40 nm, when analyzed through XRD and transmission electron microscopy (TEM) respectively. Field emission scanning electron microscopy (FESEM) was used for micro-structural investigation of samples sintered at 950?C for 4h. The investigation revealed that the material was exhibiting high dielectric constant value of 1017 at Curie temperature (T_c), 500?C when measured at 10 kHz. Impedance spectroscopy analysis showed that above 425?C, the material exhibited both bulk and grain boundary conductivities which were evidenced from FESEM studies. Density of states, minimum hoping distance, binding energy etc. were studied along with other electrical properties from impedance analysis. Hysteresis behavior was also investigated using polarization study.

Keywords

Nanomaterials, dielectrics, ferroelectrics, impedance, density of states.