【作者】 田帅；

【导师】 董国义； 韦志仁；

【作者基本信息】 河北大学 ， 光学工程， 2009， 硕士

【摘要】 本文采用水热法,分别以纯水或添加1 mol/L KOH和5 mol/L KOH作为矿化剂,填充度为35%,前驱物为In(OH)3,反应24 h合成了In(OH)3、InOOH和In2O3晶体。研究了不同温度(分别为200℃、250℃和350℃)条件下In(OH)3、InOOH、In2O3相转化规律,并对它们的形貌进行了分析。实验发现：在纯水条件下,200℃时,In(OH)3未发生晶相转化和明显的二次结晶过程,晶体无特定形貌。在250℃、350℃时,晶体结构转化成InOOH。当矿化剂浓度为1 mol/L KOH和5 mol/L KOH,温度200℃,晶体出现了二次晶化,特别是5 mol/L KOH时,最大晶体尺度达到20μm,最小晶体尺度为100 nm,显示多次晶化反应过程。当温度达到250℃时,生成InOOH晶体和少量In2O3。超过350℃,水热反应生成立方铁锰矿相In2O3,晶体边长超过50μm,显露晶面{001}、{010}、{100},以及{101}面等。以3 mol/L KOH作为矿化剂,填充度为35%,前驱物为市售In2O3(立方铁锰矿相和六方刚玉相混合物),温度为430℃,在水热条件下转化为立方铁锰矿In2O3晶体。说明在水热条件下,立方铁锰矿相较刚玉结构的六方相更稳定。采用10 mol/L KOH为矿化剂,填充度为35%,温度为430℃,在前驱物In2O3中加入摩尔百分比为10%的FeSO4·7H2O也水热合成了立方铁锰矿相In2O3晶体,Fe离子掺杂使In2O3晶体显露(101)等高指数晶面,合成产物中有部分强磁性尖晶石相Fe3O4尖晶石,显露晶面族{111}。采用化学气相法生成的立方铁锰矿相In2O3,晶体呈八面体状,显露晶面族{111},最大边长达到50μm。更多还原

【Abstract】 In this paper, In(OH)3, InOOH and In2O3 crystals were synthesized by hydrothermal method with pure water or 1 mol/L KOH,5 mol/L KOH as mineralizer, and In(OH)3 as the precursor. The fill factor is 35%, and the reaction time is 24 h. The rules of phase transformation of In(OH)3, InOOH and In2O3 were explored at different temperatures of 200℃,250℃and 350℃. and their morphologies were analyzed.It is found that the phase transformation and obvious secondary crystallization of In(OH)3 did not occurred on the condition of pure water at 200℃. The crystals didn’t have specific morphology. And the crystals transformed to InOOH at the temperature of 250℃and 350℃.When 1 mol/L KOH and 5 mol/L KOH was used as mineralizer at the reaction temperature of 200℃, the crystals turned up secondary crystallization. Especially when using 5 mol/L KOH as mineralizer, the largest crystals scale reached to 20μm and the smallest was less than 100 nm, displaying the process of multiple-crystallization. When the temperature was up to 250℃, InOOH and a few In2O3 crystals were synthesized. When above 350℃, cubic bixbyite-type phase In2O3 were synthesized. The side length of the crystal exceeded 50μm, exposing{001},{010},{100} and{101} facets.The two phases of marketable-In2O3 crystalls, cubic bixbyite-type struture and corundum-type structure, converted into cubic bixbyite-type In2O3 crystalls with 3 mol/L KOH as mineralizer. The fill factor is 35%, and the reaction temperature is 430℃. It is indicated cubic bixbyite-type phase was more stable than corundum-type phase on the condition of hydro-thermal synthesis.The cubic bixbyite-type In2O3 crystalls were also synthesized with mineralizer of 10 mol/L KOH, the fill factor of 35%, reaction temperature of 430℃, and with precursor In2O3 and 10% mol ratio FeSO4·7H2O by hydro-thermal method. The morphology had been obviously changed by doping with Fe into In2O3. The crystalls exposed high index crystal {101} facets. Part of synthetic products were ferromagnetic Fe3O4 spinel, exposing {111} facets.The cubic bixbyite-type In2O3 crystalls were also synthesized by chemistry vapour method. They appeared octahedron shape, exposing {111} facets. The maximum length of edge was 50μm.更多还原