ChemInform Abstract: Synthesis of Bismuth Germanate.

Abstract

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Room-temperature synthesis of Bi4Ge3O12from aqueous solution

“…Yukhin et al reported that a crystallized BGO powder can be formed by the dispersion of Bi 6 O 5 (OH) 3 (NO 3 ) 5 (H 2 O) 3 in an ammonium germanate solution between 333 and 363 K at a pH of 8 to 10. This phenomenon was explained as being the direct result of interaction between the solid Bi 6 O 5 (OH) 3 -(NO 3 ) 5 (H 2 O) 3 and aqueous ammonium germanate; 5) however, this same reaction is found in the present study to proceed even at room temperature at pH ≥ 3.1. In the previous reports, 5,12) there was no experiment or discussion on the intermediate states between the initial state and the final BGO formed state.…”

“…4) As a result, the synthesis of BGO powder is an important aspect of single-crystal fabrication. [4][5][6][7][8][9][10][11] The low-temperature synthesis of single-phase BGO powder has been hindered by the fact that any significant decrease in the synthesis temperature leads to impurities even when using a sol-gel method. 4,[8][9][10][11] Therefore, a temperature between 1123 and 1283 K is necessary for synthesis in air.…”

“…12) Later, in 1996, Yukhin et al reported that a highly aggregated BGO powder can be synthesized at 333 to 363 K through an interaction between solid bismuth oxyhydroxynitrate [Bi 6 O 5 (OH) 3 -(NO 3 ) 5 (H 2 O) 3 ] and ammonium germanate aqueous solution at a pH of between 8 and 10. 5) Once more though, the BGO formation mechanism and characteristics of the synthesized BGO powder were not fully explored. Referring to these solution-based processes, Henry 12) and Yukhin et al 5) considered that the BGO was formed by the reaction among the solid bismuth oxyhydroxynitrate [Bi 6 O 5 (OH) 3 (NO 3 ) 5 (H 2 O) 3 ] and GeO 4 4− polyanion in the solution, which means the reaction between the solid and the surrounding liquid.…”

“…5) Once more though, the BGO formation mechanism and characteristics of the synthesized BGO powder were not fully explored. Referring to these solution-based processes, Henry 12) and Yukhin et al 5) considered that the BGO was formed by the reaction among the solid bismuth oxyhydroxynitrate [Bi 6 O 5 (OH) 3 (NO 3 ) 5 (H 2 O) 3 ] and GeO 4 4− polyanion in the solution, which means the reaction between the solid and the surrounding liquid. Hence, a homogeneous solution was not prepared and solid Bi 6 O 5 (OH) 3 (NO 3 ) 5 (H 2 O) 3 was necessary for the BGO formation.…”

A One‐Step Synthesis of Dispersed Bismuth Orthogermanate Powder and its Performance for Alpha‐ and Gamma‐Radiation Detection

“…It is also known that Bi 6 O 5 (OH) 3 (NO 3 ) 5 (H 2 O) 3 transits into BGO when dispersed in a germanium-containing ammonia solution for 30 min and then heated to 520 °C. [32] Similarly, in [33] a suspension of Bi(NO 3 ) 3 and GeO 2 is exposured at 70 °C and pH = 2.5 (it is achieved by periodic addition of an ammonia solution) for a few hours during which bismuth germanate gradually precipitates. The reaction is considered to have reached its end when addition of ammonia resulted in a rise in the pH to 5.…”