Microstructure, dielectric, and impedance spectroscopy of the dysprosium-modified LaBiO₃ ceramic

Abstract

We report the structure, microstructure, dielectric, and transport properties of the dysprosium (Dy) modified lanthanum bismuth oxide (LaBi_0.85Dy_0.15O₃) synthesized by the solid-state reaction method. The Rietveld refinement of the X-ray diffraction (XRD) data was done using MAUD software which adopts an orthorhombic crystal system. Scherer’s formula was used to calculate crystallite size, which is found to be 25.2 nm. An analysis of a scanning electron microscope (SEM) image indicates that the grains have an even distribution throughout the whole sample surface with well-defined grain boundaries. Once more, compacted grains and clearly defined grain boundaries may have an impact on the conduction mechanism in the sample. The energy dispersive analysis of the X-ray (EDX) spectrum provides that all the constituent elements are present in the both weight and atomic percentage in the sample. The generated sample appears to reflect the Maxwell–Wagner type of dielectric dispersion, in accordance with research on the dielectric characteristics as a function of temperature and frequency. While impedance evaluation confirms the existence of the negative temperature coefficient of resistance (NTCR), the modulus plot analysis indicates a non-Debye kind of relaxation mechanism. A thermally activated conduction mechanism is present, according to the study of the ac conductivity plot. Again, the study of the Nyquist and Cole–Cole plots shows that semiconducting behavior is consistent with several applications involving energy storage devices.

Keywords:

• Orthorhombic
• crystallite size
• NTCR
• non-Debye relaxation
• Cole–Cole plots

Acknowledgment

Authors would like to thank the host Institute for XRD characterization.

Disclosure statement

No potential conflict of interest was reported by the authors.