低壓扁平焰中噴霧熱解合成YAG金屬氧化物

The Synthesis of YAG Powders by Spray Pyrolysis in Low Pressure Flat Flame

許志群(Chih-Chun Hsu)

指導教授 ： 張幼珍 ； 蔡春進 ； 林錕松

元智大學/工程學院/化學工程與材料科學學系/碩士(2006年)

摘要

本研究以低壓扁平焰噴霧熱分解技術合成金屬氧化物粉體釔鋁石榴石(yttrium aluminum garnet, YAG)，此技術原理為液體轉化成微粒並在氣相製程中進行乾燥與熱解，熱源為一低壓扁平焰。本研究中為探討YAG微粒形貌的生成機制與粉體特性，以及是否需要後處理來獲得YAG晶相，除合成YAG粉體，也嘗試單一氧化物－氧化鋁(Al2O3)及氧化釔(Y2O3)－粉體之合成。此外，研究中也嘗試製備奈米銀負載之氧化物與孔洞設計的氧化物粉體。實驗方面以甲烷過量之燃燒條件與固定操作壓力條件(~50 torr)下進行，粉體特性分析包括以掃描式電子顯微鏡(Scanning electron microscopy, SEM)與穿透式電子顯微鏡(Transmission electron microscopy, TEM)來觀察粉體，粒徑大小介於次微米到奈米間，YAG與氧化鋁粉體的形狀接近球形且分散性良好，氧化釔粉體粉體則呈現較不規則的形貌，不同先驅物鹽也會影響粉體形貌。以X光繞射(X-ray diffraction, XRD)進行化學組成判定與粉體晶格(grain size)大小之分析發現，粉體晶粒大小隨後段熱處理溫度上升而增大，此外，以X射線能量散佈分析儀(Energy dispersive spectroscopy, EDX)對製備之粉體進行元素組成比例之半定量分析。

關鍵字

金屬氧化物 ； 低壓扁平焰 ； 氧化鋁 ； 釔鋁石榴石 ； 氧化釔

並列摘要

In this study, yttrium aluminum garnet (YAG) was synthesized by spray pyrolysis in low-pressure flat flame. The techniques follow a liquid-to-particle formation process in the gas phase, with a low-pressure flat flame as the major heat source. One of the major focuses of this study was to investigate the formation mechanism for the flame-derived particle morphology. Hence, single oxides such as alumina (Al2O3) and yttrium oxide (Y2O3) were also prepared using corresponding nitrate precursors. Also, an investigation on whether post-annealing was necessary for achieving the required crystal phase was also conducted. In addition, the synthesis of metal-metal oxide composite particles and porosity-controlled metal oxide particles were also attempted. The combustion conditions used in this experiment are excess methane and the operating pressure was ~50 torr. The characteristics of the flame-derived powders were analyzed using SEM, FE-SEM and TEM. The results showed that most particles are with sizes in the submicrometer to nanometer size range. The majority of the particles were spherical except yttrium oxide. Also shown are XRD and EDX results with which the crystal phase and size, elemental composition, and atomic ratios.

並列關鍵字

metal oxides ； low-pressure flat flame ； yttrium aluminum garnet, alumina ； yttrium oxide

參考文獻

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