A Study on the Preparation and Characterization of Magnetic Nanoparticles (Co, Co@Ag, SmCo, NiPt, NiPt@SiO₂)
- Alternative Title
- 자성체 나노입자(Co, Co@Ag, SmCo, NiPt, NiPt@SiO₂)의 합성과 특성연구
- Abstract
- 본 연구는 자성재료로서 열분해법과 액상에서의 화학적 환원에 의하여 합성된 자성재료로서 Co, SmCo, NiPt의 합성방법과 특성연구를 다룬다.
1. 외부자장하에서 Co 나노입자는 사슬모양으로 배열이 되며 코일 구조로 응집된다. 유도된 외부자장사이에서 자기적 특성의 차이점은 SQIUD를 통하여 연구되었다. 뿐만 아니라 Ag를 사용하여 Ag/Co의 코어/셀 구조에 대한 연구를 수행하였으며 표면에 대한 특성연구를 다루었다.
2. 화학적 방법으로서 Sm(acac)3 과 Co(acac)3을 사용하는 SmCo의 제조방법과 특성연구를 다루었다.
3. Oleic acid와 oleyilamin 이라는 두가지 계면활성제를 사용하여 NiPt의 합성을 다루었다. 또한 합성된 입자를 실리카를 통하여 8 nm에서 16 nm의 두께로 코팅을 하였으며 이를 NiPt와 실리카 선구체와의 비를 통하여 제어할수 있었다.
In this study, the magnetic nanoparticles (Co, SmCo, NiPt) were prepared by solventless thermal decomposition and chemical reduction in liquid phase. Under the external magnetic field, the Co nanoparticles assembled into linear chains and aggregated into “pearl necklaces” coiled structures. The differences of the magnetic properties between the magnetic field induced and random cobalt nanoparticles were studied by superconducting quantum interference devise (SQUID). Further more, silver sulfate (Ag2SO4) was used to prepare the Ag shell for CocoreAgshell nanoparticles. The cobalt atoms on the nanoparticle surface acting as localized reducing agents for the silver ions. This methodology is general and may be extended to the formation of other nanoparticle core-shell systems. SmCo magnetic nanoparticles have been prepared by using Sm(acac)3 and Co(acac)2 as the precursors via chemical route. NiPt nanoparticles were one-step synthesized by reduction of nickel acetylacetonate and platinum acetylacetonate in the presence of oleic acid and oleylamine stabilizers. Silica shells were then coated with tunable thickness from 8 to 16 nm that could be controlled by varying the ratio of the NiPt nanoparticles to the silica precursor.
- Issued Date
- 2007
- Awarded Date
- 2007. 8
- Type
- Dissertation
- Publisher
- 부경대학교 대학원
- Affiliation
- 부경대학교 대학원
- Department
- 대학원 화학과
- Advisor
- 강영수
- Table Of Contents
- Ⅰ. Introduction = 1
Ⅱ. Background = 3
1. Introduction of Nanotechnology = 3
2. Nanophase Magnetic Materials = 4
2.1 Fundamentals of Magnetism = 5
2.2 Nanophase Magnetic Materials = 5
2.3 Applications of Nanophase Magnetic Materials = 6
2.3.1 Magnetic Storage = 6
2.3.2 High Power Magnets = 7
2.3.3 Biological Applications = 7
3. Synthesis Methods of Nanostructured Materials = 8
3.1 Sol-gel Synthesis = 9
3.2 Gas Phase Condensation = 9
3.3 Electrodeposition = 10
Ⅲ. Experimentations and Discussions = 11
1. Synthesis of Cobalt Magnetic Nanoparticles by Solventless Thermal Decomposition = 11
1.1 Materials = 11
1.2 Preparation of Co^(2+)-oleate₂Complex = 11
1.3 Preparation of Co Nanoparticles = 12
1.4 Characterization = 12
1.5 Result and Discussion = 13
1.6 Conclusion = 16
2. Synthesis of Cobalt Magnetic Nanoparticles and Their Assemblies by Magnetic Field = 17
2.1 Materials = 17
2.2 Preparation of Co Magnetic Nanoparticles = 17
2.3. Preparation of Magnetic Field Induced Assemblies of Co Nanoparticles = 18
2.4 Characterization = 19
2.5 Result and Discussion = 20
2.6 Conclusion = 30
3. Synthesis of Cobalt Nanoparticles and Their Conversion to Core-Shell Type of CocoreAgshell Nanoparticles = 31
3.1 Materials = 31
3.2 Preparation of Co Magnetic Nanoparticles = 31
3.3 Preparation of Core-Shell Type Co_(core)Ag_(shell) Nanoparticles = 32
3.4 Characterization = 32
3.5 Result and Discussion = 33
3.6 Conclusion = 40
4. Synthesis and Investigation of SmCo Magnetic Nanoparticles = 41
4.1 Materials = 41
4.2 Preparation of SmCo Magnetic Nanoparticles = 41
4.3 Characterization = 42
4.4 Result and Discussion = 43
4.5 Conclusion = 47
5. Chemical Synthesis and Silica Encapsulation of NiPt Nanoparticles = 48
5.1 Materials = 48
5.2 Preparation of NiPt Nanoparticles = 48
5.3 Silica Coating of NiPt Nanoparticles = 49
5.4 Characterization = 49
5.5 Result and Discussion = 50
5.6 Conclusion = 59
Ⅳ. Summary = 60
Ⅴ. References = 62
Ⅵ. Korean Summary = 66
- Degree
- Master
- Files in This Item:
-
-
Download
A Study on the Preparation and Characterization of Magnetic Nanoparticles (Co, Co@Ag, SmCo, NiPt, Ni.pdf
기타 데이터 / 1.2 MB / Adobe PDF
-
Items in Repository are protected by copyright, with all rights reserved, unless otherwise indicated.