Department News
FABRICATION AND SIZE-SELECTION OF NANOPARTICLES
Seminar Date
2003-04-25
Author
안지영
Date
2003-04-25
Views
1564
1. 제 목 : FABRICATION AND SIZE-SELECTION OF NANOPARTICLES
2. 연 사 : Dr. Takafumi Seto
(National Institute of Advanced Industrial Science and Technology, JAPAN)
3. 일 시 : 2003년 4월 30일 (수) 16:00 – 17:00
4. 장 소 : 301동 117호
5. 내 용 :
Studies on nanometer-sized particles (nanoparticles) have progressed rapidly over the past decade. Nanoparticles have properties distinct from those of bulk materials, and their potentials for application are attracting attention. This paper presents the method for fabricating size-selected semiconductor and metal nanoparticles (Si, Ni, Co, etc., diameter; 5 to 20 nm). The nanoparticles were synthesized by a series of sequential gas-phase processes including pulsed laser ablation, aerosol post-annealing, size-classification, compulsory oxidation, and aerosol-jet deposition. The change in the size distribution of the generated particles due to post-annealing was measured by a low-pressure differential mobility analyzer (LP-DMA) coupled with a Faraday cup electrometer. The peak size decreased as the post-annealing temperature rose, indicating that a sintering and re-structuring of the agglomerates was taking place. In the high-resolution TEM (HR-TEM) observation, the Ni particles of less than 15 nm in diameter were found to be spherical and single crystal after the annealing at 1073 K. The 20 nm particles were also spherical, but they remained polycrystalline due to a lack of annealing required for re-crystallization. The change in the surface morphology due to the compulsory oxidation was analyzed by the HR-TEM and electron diffraction. Finally, monodispersed (geometric standard deviation < 1.2) core-shell particles with oxidized surface layers of 2 nm and particle diameters ranging from 5 to 20 nm were successfully fabricated. The various properties of generated core-shell nanoparticles will be also presented. .
6. 문 의 : 기계항공공학부 최만수 교수 (☏ 880-7128)
2. 연 사 : Dr. Takafumi Seto
(National Institute of Advanced Industrial Science and Technology, JAPAN)
3. 일 시 : 2003년 4월 30일 (수) 16:00 – 17:00
4. 장 소 : 301동 117호
5. 내 용 :
Studies on nanometer-sized particles (nanoparticles) have progressed rapidly over the past decade. Nanoparticles have properties distinct from those of bulk materials, and their potentials for application are attracting attention. This paper presents the method for fabricating size-selected semiconductor and metal nanoparticles (Si, Ni, Co, etc., diameter; 5 to 20 nm). The nanoparticles were synthesized by a series of sequential gas-phase processes including pulsed laser ablation, aerosol post-annealing, size-classification, compulsory oxidation, and aerosol-jet deposition. The change in the size distribution of the generated particles due to post-annealing was measured by a low-pressure differential mobility analyzer (LP-DMA) coupled with a Faraday cup electrometer. The peak size decreased as the post-annealing temperature rose, indicating that a sintering and re-structuring of the agglomerates was taking place. In the high-resolution TEM (HR-TEM) observation, the Ni particles of less than 15 nm in diameter were found to be spherical and single crystal after the annealing at 1073 K. The 20 nm particles were also spherical, but they remained polycrystalline due to a lack of annealing required for re-crystallization. The change in the surface morphology due to the compulsory oxidation was analyzed by the HR-TEM and electron diffraction. Finally, monodispersed (geometric standard deviation < 1.2) core-shell particles with oxidized surface layers of 2 nm and particle diameters ranging from 5 to 20 nm were successfully fabricated. The various properties of generated core-shell nanoparticles will be also presented. .
6. 문 의 : 기계항공공학부 최만수 교수 (☏ 880-7128)
