The microstructure and phase transformations of copper-doped BiNbO 4 ceramics synthesized at 950 and 1100 & # 176; C are investigated. According to XRD data, samples in a compact, pressed form crystallize in the ?-BiNbO 4 structure, regardless of the synthesis temperature and in spite of the phase transition ?. & # 8594; ? at 1040 & # 176; С. BiNb 1 & ndash; x O 4 & delta; xCuO (x & le; 0.04) preparations are graphite-colored composites with a visually pronounced grain microstructure. The thermograms of the samples show an endothermic effect near 900 ° C, associated with the decomposition of copper (II) oxide, and heat effects due to the occurrence of reconstructive phase transformations in BiNbO 4 of the ?; & # 8594; .gamma; & # 8594; ?. It was found that an impurity of copper oxide in the ceramics of bismuth orthoniobate acts as a heat sink, which leads to an increase in the phase transformation temperature .alpha. & # 8594; .gamma; when heating compact samples
Cand. chem. Sciences N. A. Zhuk 1 (This email address is being protected from spambots. You need JavaScript enabled to view it.), Ya. A. BUSARGINA < sup> 1 , cand. chem. Sci. V. A. BELY 2 , Cand. geol.-mineral. B. A. MAKEEV 3 ;
1 Syktyvkar State University (Russia, Syktyvkar)
2 Institute of Chemistry, Komi Science Center, Ural Branch of the Russian Academy of Sciences (Russia, Syktyvkar)
3 Institute of Geology, Komi Science Center, Ural Branch of the Russian Academy of Sciences (Russia, Syktyvkar)
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