微量SF6對鋯鈦鎳金屬玻璃薄膜之影響與性質之探討

Abstract

有別於傳統的金屬材料，金屬玻璃材料是由熔融態經過快速冷卻而得到的非晶質合金。因為不規則的原子排列與晶界之缺乏，金屬玻璃擁有諸多特殊的性質，優異的機械性質、良好的抗腐蝕性質與軟磁性等，數年來吸引許多學者競相投入相關的研究。然而，金屬玻璃的高製造技術層次與最為人詬病的脆性特徵限制了其在工業上或是大尺度結構件的應用。而金屬玻璃薄膜的誕生，為金屬玻璃領域帶來了嶄新的一頁。就如同金屬玻璃，金屬玻璃薄膜繼承了其相關的卓越機械、腐蝕性質等，此外，有別於金屬玻璃的嚴苛製程，簡單的靶材濺鍍即可得到非晶質金屬玻璃薄膜。拜簡單的製程所賜，我們可以透過操控成分以達到更佳的機械性質或是特殊的應用，大大地增加了金屬玻璃薄膜運用的靈活性。本實驗探討氟與硫摻雜對鋯鈦鎳金屬玻璃薄膜性質之影響。藉由在濺鍍過程中，微量通入常見的惰性氣體六氟化硫來改善鋯基金屬玻璃薄膜之機械性質。實驗發現在金屬玻璃薄膜中摻雜大約6%的氟原子即能將硬度提升至未含氟金屬玻璃的兩倍以上。研究指出在金屬非金屬系統中，高電負度的氟原子會佔據中心被吸引其他原子形成短程有序的結構，而使得機械性質提升。透過電子能譜儀分析，得以確認高電負度的氟原子與鋯原子形成鍵結。於高解析穿透式電子顯微鏡觀察中，奈米晶粒與短程有序的共存，會造成彼此互相鎖合，而使得機械性質提升。

Metallic glass, or bulk glassy alloy (BGA), is a kind of metal which is generally fabricated by extremely rapid quenching. Therefore, Metallic glasses are noncrystalline alloys lacking long-range atomic periodicity. Because of the absence of grain boundaries and disordered atomic structure, BMGs have some superior properties. However, poor ductility significantly restricts the application of BMGs. Due to easier fabrication, thin film metallic glass (TFMG) having all the advantages of BMGs has drawn lot of attentions. In this thesis, properties of fluorine and sulfur doped Zr-Ti-Ni thin film metallic glasses were studied. While sputtering with 0.3 sccm SF6, hardness of Zr-Ti-Ni TFMG with only about 6% fluorine was higher than Zr-Ti-Ni TFMG for two times. HRTEM proved that high electronegativity F would attract other atoms to form short range orders (SROs) or nanograins embedded in the amorphous matrix. SROs and nanograins would interlock with each other and thus gave rise to the maximum mechanical properties. Through XPS analysis, the potential bindings and compounds would be investigated. High electronegativity F bound with Zr or reacted with it to form ZrF4. Therefore, it could be speculated that clusters and nanograins indeed existed and might consisted of Zr and F atoms.