2nd Edition of World Nanotechnology Conference

April 27-29, 2020 | Baltimore, USA

Crowne Plaza Hotel Baltimore Dowtown –
Inner Harbor, 105 W Fayette Street
Baltimore, MD 21201 USA
Phone : 1 (702) 988 2320
Toll Free: 1800–883-8082
Whatsapp: +1 (540) 709-1879
Email: worldnano@magnus-group.org
April 27-29, 2020 | Baltimore, USA

Yanli Li

Speaker for Nanomaterials Conferences
Yanli Li
Chinese Academy of Sciences, China
Title : Enhancement of properties of HfO2-coated glass monocapillary

Abstract:

The glass monocapillary X-ray optics works based on total external reflection of X-rays. And a glass monocapillary with inner high-density film coating is expected to improve the transmission characteristics. Here ~150 nm HfO2 film is deposited on the inner wall surface of the tapered glass monocapillary with entrance diameter 596.4 μm, exit diameter 402.3 μm and length 9.9 cm by atomic layer deposition (ALD). The full energy spectrum and the light intensity gain of X-rays focused by monocapillary before and after coating are measured and calculated. As one of the theoretical advantages, energy broadening of focused X-rays is observed by using HfO2-coated glass monocapillary. The highest energy of X-ray is improved from ~18 keV to ~33 keV and the light intensity gain of X- rays between 16 keV and 20 keV reaches 2.5, which is the result of more higher energy X-rays from the W X-ray tube being totally reflected on the inner wall of the HfO2-coated glass monocapillary due to the increase of total reflection critical angle. In addition, HfO2-coated glass monocapillary shows ability to suppress the ‘penetration halo’ because  of the absorption of more high energy X-rays by the HfO2 film. Besides that, ~50 nm HfO2 film is deposited on the inner wall surface of another tapered glass monocapillary with entrance diameter 459 μm, exit diameter 374 μm and length 5 cm also by ALD. The ~50 nm HfO2-coated monocapillary is used in X-ray fluorescence (XRF) experimental system. Comparing the two energy spectra of sample Mo obtained by uncoated and coated monocapillaries, the  energy spectrum of HfO2-coated monocapillary appears two new peaks at ~17.4 keV and ~19.6 keV. It’s because that the X-rays focused by HfO2-coated monocapillary is higher than the absorption edge of Mo and the characteristic peaks of Mo are excited, which also indicates the extension of the energy range of the X-rays focused by HfO2-coated monocapillary.

Audience take away:

•    Highly homogeneous thin film (several angstrom) can be deposited on the surfaces of flat and curved substrates by ALD.
•    High-density film coated capillary can be used in micro-XRF to excite higher energy characteristic peaks of the sample.
•    High-density film coated capillary can be used in X-ray microscope to obtain high resolution.

Biography:

Dr. Y. Li studied Electrical Engineering at Hebei University of Technology, China and graduated as BEng in 2012. She then joined the research group of Prof. L. Han at the Institute of Electrical Engineering, Chinese Academy of Sciences (IEE-CAS). She received her PhD degree in 2018 at the same institution. And then she obtained the position of an Research Assistant at the IEE-CAS. Her research field is the preparation of thin film materials and thin film devices.

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