本篇論文的研究內容大致上區分為儀器測試及氧化鈮原子團簇 的生成.結構穩定性及其游離能的研究兩個部份. 在儀器測試部份中,我們測試了各種不同結構的rod holde r對鈮原子團簇訊號的影響.由測試結果中發現,在分子束噴嘴口徑與r od holder口徑的比例大約為1:2時,可以生成Nbn+ n =1-18 的鈮原子團簇;此外,在測試結果中亦發現,rod ho lder中的擴展零件可以加強原子團簇的訊號強度.在氧化鈮原子團簇 的研究部份中,我們利用在分子束氣體中氧氣含量的改變, 發現了結構 中各種不同氧原子含量的氧化鈮原子團簇.此外,藉由計算各種氧化 鈮 原子團簇的總價電子數所發現的價電子數規律性,我們引用了 ”12- electron rule”來解釋其結構組成及其穩定性.而在氧化 鈮原子團簇的游離能研究方面,由結果發現除了Nb7-10O1-5 能被實驗中218nm波長的雷射光游離外,其餘曾在離子訊號中發現過 的氧 化鈮原子團簇皆不能被游離,因此我們由實驗結果認為這些氧化鈮 團簇的 游離能高於5.7ev. In thesis, it has been divided for twoparts;one is the inspect ion of the functionfor the TOF m ass spectrometry,and the otheris the studies of formation,struct ural stability and ionization po tentials of niobium oxide cluste rs. In the section of instrumen tal inspection,we investigated t he influence of rod holder geome try for the signals of nionium c lusters.From the results,Nbn+ (n =1-18)could be producedunder the condition,where the ratio of no zzlediameter to rod holder diame ter is 1:2.In addition,the exten sion segment with 10 expansion c ouldenhance the signal intensity . In the section of studies of niobium oxide clusters,niobium o xide clusters with different sto ichiometrieshave been observed b y varying the oxygen concentrati onin molecule beam.The valence e lectron regulation wasapplied to explain the stability of these niobium oxideclusters. In the s tudies of ionization potentials of niobiumoxide clusters,we cann ot find any signals of neutral n iobium oxide clusters at 218nm l aser wavelength,except Nb7-10O1- 5 clusters.Thus that the ionizat ion potentials of these spices e xcept Nb7-10O1-5 clustersare hig her than 5.7ev.
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