加熱高熵合金粉可得新型螺旋型氧化鋁奈米線，且鉻會在氧化鋁奈米線成長的過程中自然溶入，此種奈米線具藍綠光譜且在662 nm處有一小光譜值；奈米線符合場發射曲線且有一低臨界電壓值。CASTEP計算結果顯示單一矽原子取代氧原子並不會影響其物理性質，但取代兩個氧於不同位置、或不同的鋁位置及位於插入位置時都會影響氧化鋁結構的性質；在奈米結構的計算中，氧化鋁奈米結構表面的鋁及氧原子會在價電代邊界與導電帶之間形成許多新能帶，且在能量損失計算中亦會形成許多新的峰值，並且整個曲線向低能量處偏移。當等莫耳鋁和矽粉加熱後可得到四種奈米結構，特別是鋁奈米線最引人注目，而此奈米線也採用不同的方式加以分析。

本論文共分四部份：1.利用高熵合金系統合成氧化鋁奈米線；2.氧化鋁奈米結構的CASTEP計算；3.在鋁矽系統中合成氧化鋁奈米結構；4. 在鋁矽系統中合成鋁奈米線。

The novel spiral alumina nanowires are produced via the annealing of HEAs and it is found that Cr is automatically incorporated into the alumina during the nanowire growth. Nanowires exhibit a blue-green light, together with a small emission at 662nm. Nanowires show a well-defined field emission profile and lower threshold field. CASTEP calculations show that single substitution occurs at different O sites will not influence the physical properties, whereas Two-substitution of O site, different Al-substitution by Si and interstitial, will influence physical properties of alumina cell. The Al and O atoms on surface of nanostructure will create many sub-bands between upper valance and conduction band, and peaks are shifted to lower energy in loss function profiles. Equimolar mixture of fine Al and Si powder annealed generates four kinds of nanostructures especially of aluminum nanowires, which are characterized accordingly.

This thesis consists of four parts, (1) synthesis of alumina nanowires using HEA system; (2) CASTEP calculation of alumina related nanostructres, (3) synthesis of alumina nanostructures in an Al-Si system; (4) synthesis aluminum nanowires in an Al-Si system

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