Abstract

The inluence of the heat treatment conditions and of the time of hydrothermal treatment at 210°С on the phase composition and size of crystallites and nanoparticles of lanthanum orthophosphate (LaPO₄) was considered. The heating conditions in the course of hydrothermal synthesis of LaPO₄ influence the structural transition of lanthanum orthophosphate of rhabdophane structure into the phase of monazite structure, and also the particle morphology and crystallite size. The phase of monazite structure with the crystallite size of approximately 12 nm without rhabdophane impurity is formed after hydrothermal treatment at 210°С for 30 min in the case of microwave heating of the hydrothermal fluid. When using external heating of autoclaves, at the same temperature inside the autoclave, the mean size of the crystallites of the monazite phase formed is 17 nm.

中文翻译：

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水热处理条件对独居石结构正磷酸镧纳米粒子形成的影响

摘要

考虑了热处理条件和210°С水热处理时间对正磷酸盐镧（LaPO ₄）的微晶和纳米粒子的相组成和尺寸的影响。LaPO ₄水热合成过程中的加热条件影响菱锰矿结构的正磷酸镧的结构转变为独居石结构的相，并且影响颗粒形态和微晶尺寸。在微波加热水热流体的情况下，在210°C进行水热处理30分钟后，形成了微晶尺寸约为12 nm的独居石结构相，其中没有生辉石杂质。当使用高压釜的外部加热时，在高压釜内的相同温度下，所形成的独居石相的微晶的平均尺寸为17nm。