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1091-專題演講-1091014-陳詩芸(台科大材料系)

演講活動
張貼人:李明芳公告日期:2020-08-18
  
Time1091014 (Wed.) 14:20~16:20
SpeakerProf.陳詩芸(CHEN, Shih-Yun)
國立臺灣科技大學材料科學與工程系/Department of Materials Science and Engineering, National Taiwan University of Science and Technology
TitleMagnetism and plasmonic performance of mesoscopic hollow ceria spheres 
AbstractFirstly, magnetism of mesoscopic hollow ceria sphere with different defect distribution was investigated. Micro-scale hollow spheres were synthesized by spray pyrolysis and then immersed in 1 M HNO3 for different times. The content and distribution of defect were investigated by complementary microscopic and spectroscopic analysis. It is demonstrated that the value of saturation magnetization varies with sphere structure, including defect distribution character and surface roughness. The strongest magnetism was obtained in the sample subjected to react with 1 M HNO3 for 60 minutes, in which Ce3+ aggregates within a narrow defective layer at surface and the sphere surface is smooth. It thus implied that in micro-scale hollow sphere, surface plays the major role in its magnetic behavior.
Next, the role of interfaces and surfaces on the surface enhanced Raman spectroscopy (SERS) properties of CeO2 hollow spheres decorated by Ag nanoparticles (H-CeO2@Ag) were investigated. The composites, H-CeO2@Ag, were synthesized using a newly developed two-step process. Spectroscopic and microscopic characterization confirms the formation of an interface between the Ag and ceria and shows different charge rearrangements occurring at both the interface and surface. Strong SERS effect was reported with a detection limit down to 10-14 M for rhodamine 6G analytes. Scanning transmission electron microscopy and electron energy loss spectroscopy investigation reveals that hot-spots are associated with the silver NPs surfaces and also with Ag/ CeO2 interface. This interfacial hot spot occurs for metallic particles above 30 nm and is strongly red shifted with respect to the Ag surface plasmon. The strong SERS activity is then attributed to the presences of several types of hot-spots and the geometrical features (buoyant hollow sphere, size dispersion) of the composite. 
PlaceB101, Gongquan Campuses, NTNU

最後修改時間:2020-10-12 PM 2:35

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單位簡介

本系的重點研究領域包括:凝態物理、光電與奈米科學、高能與粒子物理、軟凝態物理與生物物理、原分子光學物理、及物理科學教育等。本系前身為臺灣省立師範學院理化系物理組,成立於民國三十五年(1946年)本校創校之始。民國五十一年(1962年)本系獨立成系,民國六十三年(1974年)成立物理研究所碩士班,民國八十年(1991年)成立研究所博士班。長久以來,本系肩負著培育臺灣中等學校物理科師資的重任,但也不忘在物理學術研究上求新求進步。至今本系培育出的學術人才已有一位中研院院士及近百位中研院研究員及大學教授,各行各業的高科技人材更是不勝枚舉。民國八十三年師資培育法改制後,本系已升級為尖端學術研究、科技應用研發、及中學師資培育三者齊備的系所。

  • 國立臺灣師範大學物理系系友會
  • 系友會線上小額捐款
  • 徐有庠盃-臺灣青年學生物理辯論競賽
  • 國際物理奧林匹亞競賽
  • 公用場地與儀器設施預約系統
  • 學生實習專區
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