X-ray and Spectroscopic Characterization of Molybdenum doped Lithium and Sodium Tungsten Bronzes

School of Environmental Science and Management, Independent University* Department of Chemistry, University of Dhaka, Bangladesh** Institute of Mineralogy, University of Hannover, Germany***
○KALPANA RANI DEY* Dr. Altaf Hussain** Claus H. Ruscher***

In the present investigation powder samples of LixMoyW1-yO3 (x = 0.1, 0.4, and y = 0.02 0.4) and NaxMoyW1-yO3 (x = 0.6 and y = 0.05 0.25) have been prepared by solid state reaction in evacuated silica tubes with synthesis temperature 700°C. From X-ray powder diffraction pattern of Li0.1MoyW1-yO3 system, it is observed that with increasing Mo content the proportion of PTBtetr decreases and a phase of orthorhombic symmetry increases with a small amount of impure phase Li2W4O13. This X-ray result is supported by IR absorption spectra of the samples. Whereas, in the system Li0.4MoyW1-yO3 the proportion of PTBCubic phase reduces with increasing molybdenum content. In presence of small amount of Mo, a Li2W2O7 type phase is formed along with PTBCubic phase.
From the X-ray powder diffraction patterns of Na0.6MoyW1-yO3 system, a PTBCubic phase is observed with y 0.1 . However, for y > 0.1 an extra phase of Na2Mo2O7 is also observed along with PTBCubic phase.