過去前人的文獻中，以氧化釔(Y2O3)作為對象的相關研究，多半為合成多元素氧化物之探討，對於單一元素氧化釔礦物之研究不多。根據先前的研究中指出，利用母體(Y2O3，TiO2，ZrO2)的粒徑控制合成目標粉末(Y3Al5O12，BaTiO3，BaZrO3)粒徑，其原理係藉由Al及Ba成份分別擴散進入特定粒徑的Y2O3、TiO2及ZrO2粒體而得。即藉由調整原料粉末之粒徑，可達到合成特定粒徑的粉末；因此，如有適當大小粒徑之Y2O3粒體粉末，則有機會合成對應粒徑之YAG粒體粉末。本研究藉由觀察氧化釔之粗化現象作為未來獲得特定粒徑Y2O3粉末的依據，對後續粗粒徑之YAG合成上必有相當的助益。研究以Ostwald ripening觀點，觀察氧化釔粒體粗化時，若改變氧化釔粒體粗細粒子配位數，其成長速率是否改變。
本實驗使用三種不同粒徑氧化釔(Y2O3)粉末：50nm(S)，100nm(M)，200nm(L)。藉其粒體粒徑不同所形成的配位數比(Ns)，配製成SM(50nm+100nm)和SL(50nm+200nm)兩組樣品，每組樣品再根據小球總表面積/大球總表面積比的不同，配製為SM：8/1、4/1、16/1以及SL：5.5/1、2.75/1、11/1共六組起始樣品，分別從室溫直接置入特定高溫(1300℃，1400℃)進行煅燒。每一組樣品皆有數種不同持溫時間，煅燒後之粉末樣品經處理後量測其BET值，計算各樣品之粗化速率。
實驗結果得知氧化釔成長機制應為Ostwald ripening。由TEM照片可觀察到氧化釔顆粒的圓化，此為小顆粒溶解消失前的證據(Ostwald ripening現象)，並在較大顆粒周圍觀察到非晶質體的存在，與文獻中Ostwald ripening機制提及的現象相同。
於晶粒成長速率與平均直徑變化關係圖中，六組樣品隨著較細粒體總表面積的增多，SM16/1、SL11/1樣品擁有最高的粗化速率，應為其較小顆粒數來源充足，有助於粒體成長，然而隨著持溫時間的拉長粒體間產生了凝聚結球的現象，使得後段各樣品的成長速率皆提高。比較SM和SL樣品組，可知溫度和配位數對於粒體的成長粗化是重要的兩個參數。將晶粒成長速率方程式(Grain growth rate equation)整理後可由(D3-D03)與(t-t0)關係圖上斜率比較樣品組之間的k´(速率常數)大小。由SM和SL樣品組中皆可觀察到(Fig.13(a)~(d)) SM：16/1及SL：11/1之樣品速率常數最大，其樣品成長速率最快，反之SM：4/1及SL：2.75/1之樣品成長速率最低。以Ostwald ripening的觀點來看亦即大顆粒成長所需的小顆粒溶解來源變多，也即促進晶粒成長的來源較多，反應速率越快。

In past researches, yttrium oxide related discussions were limited to compound oxides, but few on solely yttrium oxide itself. According to preceding researches, the target powder (Y3Al5O12，BaTiO3，BaZrO3) grain diameter was synthesized by controlling the matrix (Y2O3，TiO2，ZrO2) grain diameter. The process diffuses the Ba content into the TiO2、ZrO2 grain bodies, then diffuse the Al content into the Y2O3. By tuning the grain diameter of the powders from different materials, the powder with the target grain diameter can be synthesized hence if there is Y2O3 grain powder with the right grain diameter, there is a chance to get the YAG grain powder with the respective grain diameter. By observing coarsening between the yttrium oxides, the data found can aid in the synthesis of the YAG with coarse grain diameters.
This research uses yttrium oxides (Y2O3) with three different grain diameters: 50nm(S)，100nm(M)，200nm(L). Due to the fact that the grain diameters create different coordination number, even when coarse grains are surrounded by the smooth grains, the coarse smooth grains ratio will produce SM：8/1、4/1、16/1 and SL：5.5/1、2.75/1、11/1. Each are separately placed from room temperature to the designated high temperature (1300℃，1400℃) for calcination. Every sample will have kinds of different calcining times. After calcination the BET value of the powder is measured after it has been processed, then the efficiency of the coarse granulation.
As shown in the experimental results the coarsening mechanism of yttrium oxide is Ostwald ripening. Grains rounding can be observed in the TEM images, also exists amorphous bodies. Using Grain growth rate equation to deduct the growth formula of grains to organize the formula to (D3-D03) and (t-t0) relation graphs to find the slope value k’. The study show little amounts of small grains have bigger k’, whereas more amounts the k’ is lower. Using Ostwald ripening perspective the bigger grains need more small grain solvents to enable more grain growth. The reverse is when there are more contact points, the reaction becomes accelerated.

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