The growth units and hydrothermal preparation of lead tungstate (PbWO_4) crystallites

来源 :Science in China(Series E:Technological Sciences) | 被引量 : 0次 | 上传用户:yunzh
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The crystal structure of lead tungstate (PbWO4) can be regarded as ordered combination of the tungsten oxide tetrahedrons (WO4) and lead ions (Pb2+). According to the growth unit model, the growth units of lead tungstate are the aggregations of the tungsten oxide tetrahedrons and lead cations with various geometry configurations. It is suggested that the favorable growth units of lead tungstate crystal are pyramidal, tetragonal prism and quadrangular units corresponding to geometric orientations of the simple forms of the crystal. Under low restricted growth conditions, the growth form of lead tungstate crystallites is the aggregation of the geometric configurations of these favorable growth units. The above conclusions are completely confirmed by the experiment on hydrothermal preparation of lead tungstate crystallites. The crystal structure of lead tungstate (PbWO4) can be regarded as an ordered combination of the tungsten oxide tetrahedrons (WO4) and lead ions (Pb2 +). According to the growth unit model, the growth units of lead tungstate are the aggregations of the tungsten oxide tetrahedrons and lead cations with various geometry configurations. It is suggested that the favorable growth units of lead tungstate crystal are pyramidal, tetragonal prism and quadrangular units corresponding to geometric orientations of the simple forms of the crystal. Under low restricted growth conditions, the growth form of lead tungstate crystallites is the aggregation of the geometric configurations of these favorable growth units. The above counters are confirmed completely by the experiment on hydrothermal preparation of lead tungstate crystallites.
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