查詢結果分析
來源資料
相關文獻
- Synthesis and Structural Features of a Flux-Grown Hematite
- Structural Characterization of a TlCaBaCu Oxide in Tc onset=155K and Tc zero=123K Superconducting Specimens
- Structural and Microstructural Characterization of a High Tc Superconducting BiSrCaCu Oxide
- 高溫超導體專輯
- 高溫超導銅氧化合物之結構與特性解析
- Isolation and Application of Thermotolerant Microbes in Composting
- Effect of Ultraviolet-C Irradiation on Volatile Compounds of Common and High-Temperature Mushrooms
- 短波紫外線照射對洋菇和高溫菇儲藏品質之影響
- 高溫放線菌之纖維素酶活性及對稻草堆肥品質之影響
- 火力電廠氣渦輪機高溫油泥問題解決案例--含新油開發及水冷卻效率計算
頁籤選單縮合
題 名 | Synthesis and Structural Features of a Flux-Grown Hematite=鏡鐵礦之助熔法合成及結構特徵 |
---|---|
作 者 | 余樹楨; 李建興; 董淑芳; 藍錦龍; | 書刊名 | 中國地質學會會刊 |
卷 期 | 42:3 1999.08[民88.08] |
頁 次 | 頁349-358 |
分類號 | 357.83 |
關鍵詞 | 合成赤鐵礦; 鏡鐵礦; 助融法長晶; 高溫; 晶體結構; Synthetic hematite; Specularite; Flux growth; High temperature; Crystal structure; |
語 文 | 英文(English) |
中文摘要 | 以助熔法合成祖母綠實驗中,一種閃亮異常、近乎純氧化鐵成份的鏡鐵礦晶體同 時結晶出來。所培育鏡鐵礦為0.5毫米厚、10毫米大的片狀晶體;晶面上出現可能是雙晶的 條紋狀顯微構造。長晶步驟包含兩階段的冷卻過程:首先自1200℃以每小時0.5℃的速率緩 慢冷卻至1000℃,第二階段則以每小時1℃的速率自1000℃冷卻至900℃。 以兩顆合成鏡鐵礦晶體所進行的結構分析結果同時顯示人造鏡鐵礦晶體結構中的鐵氧鍵 長均略小於天然赤鐵礦的鐵氧鍵距。本合成鏡鐵礦原子排列中最具特色的是八面體配位鐵離 子的電子雲分布。鐵離子的熱振動橢球沿(001)面明顯呈現扁平化偏移,這是反應相鄰兩鐵 離子距離太近所產生相互排斥的結果。由於鐵離子外圍電子雲的扁平分布,因此有效減低正 電排斥作用,因而使原本不安定的陽離子共面鏡鐵礦結構轉趨於穩固。 |
英文摘要 | Almost pure Fe O hematite crystals exhibiting a superior metallic luster were produced in an emerald synthesis experiment using a flux-growth process. The grown specular hematites were platy crystals approximately 0.5 mm thick, 10 mm long and 10 mm high, exhibiting apparent twinning boundaries on the crystal surface. The growth was initiated at 1200℃, in a platinum crucible, followed by a two-stage slow cooling process. The first stage involved cooling from 1200 ℃ to 1000℃ at a cooling rate of 0.5℃/h; the second stage was from 1000℃ to 900℃ at 1℃/h. A detailed crystal structure analysis was carried out with two separate synthetic crystals. The structural refinements indicate that the interatomic distances of various bonds are shorter than the corresponding lengths in natural samples. This is a direct consequence of the impurity-free chemical composition of the grown crystals. The most significant structural characteristic in the synthetic hematite is the electron chare distribution surrounding the ferric ion in the octahedral position. The thermal ellipsoid of the Fe ion is flattened in the (001) plane to form an oblate spheroid. This is in response to the adjacent iron atoms repelling one another along the [001] direction .The dispersed electron charge perpendicular to the c-axis significantly reduces the repelling effect between two adjacent Fe atoms. This stabilizes the otherwise unstable face-sharing octahedral structure. |
本系統中英文摘要資訊取自各篇刊載內容。