Synthesis and characterization of Bi³⁺ and V⁵⁺ co-substituted La₂Mo₂O₉

ABSTRACT

Solution combustion route was employed for synthesis of the parent, La₂Mo₂O₉ and its derivatives with formula La_2-xBi_xMo_1.95V_0.05O_9-δ (0.200$\le x\le$0.075). Powder X-Ray diffraction, SEM, DSC and impedance spectroscopy techniques were used to characterize the synthesized compounds. The results of structural, thermal and temperature dependent conductivity confirm the room temperature stabilization of the cubic phase in all the doped compounds. All the doped compounds exhibit enhanced electrical conductivity with respect to the parent compound in intermediate temperature range where as compounds with x = 0.075 and x = 0.100 show higher electrical conductivity compared to the vanadium substituted compound, La₂Mo_1.95V_0.05O_9-δ, throughout the whole temperature range. In the cubic region of La₂Mo₂O₉, conductivity is slightly enhanced compared to the parent compound for the composition x = 0.100. However, it is lower in the case of single vanadium doped compound [1]. The highest conductivity is obtained for the composition x = 0.100 at temperature 750°C and the value is 0.041 S.cm⁻¹.

KEYWORDS:

• Oxide ion conductor
• ionic conductivity
• diffusion of oxygen vacancies
• impedance spectroscopy

Acknowledgement

The author acknowledges the DST for providing FIST facility in the Department of Physics, North Eastern Regional Institute of Science and Technology (Sanction order No. SB/52/CMP-093/2013) and the funding agency DST, India for providing INSPIRE Fellowship to one of the authors (AJS).

Disclosure statement

No potential conflict of interest was reported by the authors.