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• 作者：Prangya Parimita Sahoo ; Etienne Gaudin ; Jacques Darriet ; T. N. Guru Row
• 刊名：Inorganic Chemistry
• 出版年：2010
• 出版时间：June 21, 2010
• 年：2010
• 卷：49
• 期：12
• 页码：5603-5610
• 全文大小：1049K
• 年卷期：v.49,no.12(June 21, 2010)
• ISSN：1520-510X

文摘

A new solid solution Pb_3−xBi_2x/3V₂O₈ (0.20 ≤ x ≤ 0.50), stabilizing the high-temperature γ form of Pb₃V₂O₈, has been isolated in the system Pb₃V₂O₈−BiVO₄. The single-crystal structure of the composition x = 0.50 (Pb_2.5Bi_1/3V₂O₈) was solved using single-crystal X-ray diffraction (XRD) technique. The compound crystallizes in the trigonal crystal system Rm (No. 166) with a palmierite structural type with a = 5.7463(3) Å, c = 20.3047(12) Å, V = 580.64(5) ų, and Z = 3. The final R1 value of 0.0406 was achieved for 217 independent reflections during the structure refinement. The variable-temperature powder XRD shows the absence of any phase transition for all of the members of the solid solution in the limit of 398−80 K. The new solid solution has been characterized by neutron powder diffraction, solid-state UV−vis diffuse-reflectance spectra, scanning electron microscopy, and X-ray photoelectron spectroscopy (XPS). Alternating-current impedance studies indicate conductivity on the order of 10⁻⁴ Ω⁻¹ cm⁻¹ for Pb_2.5Bi_1/3V₂O₈. The change in color of the samples from brown to yellow at high temperature was explained by XPS studies, which indicate the plausible formation of the ppm level of Bi₂O₃ at such elevated temperature ranges.