Effect of annealing-temperature-assisted phase evolution on conductivity of solution combustion processed calcium vanadium oxide films

• DOI: 10.1007/s12034-018-1644-9
• Publication Date: 2018-09-08T04:00:25Z
• Authors: G Manjunath; Robbi Vivek Vardhan; Ashritha Salian; Rashi Jagannatha; Mayank Kedia; Saumen Mandal
• Keywords: 01 natural sciences; 0104 chemical sciences

In this work, the effect of annealing temperature on the conductivity of solution-combustion-synthesized calcium vanadium oxide (CVO) films was studied. Conductivity was tailored by the appearance of the phases like $$\hbox {CaVO}_{3}$$ , $$\hbox {CaV}_{2}\hbox {O}_{5}$$ and $$\hbox {Ca}_{2}\hbox {V}_{2}\hbox {O}_{7}$$ as a function of annealing temperature; $$\hbox {CaVO}_{3}$$ and $$\hbox {CaV}_{2}\hbox {O}_{5}$$ are responsible for high conductivity, whereas $$\hbox {V}^{5+}$$ presence in $$\hbox {Ca}_{2}\hbox {V}_{2}\hbox {O}_{7}$$ contributes towards dielectric nature. Evolution of phases of CVO was identified through X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. A detailed conductivity measurement as a function of annealing temperature helps us to identify the decreasing trend of conductivity with increasing temperature up to $$400{^{\circ }}\hbox {C}$$ ; beyond this it behaves like an insulator. There was a stable conductivity while aging the films in ambient for a few days. This study revealed safe application temperature domain of CVO, and a clear correlation of electrical conductivity with the in-depth structural–compositional–morphological study.