Eylem Seç
Exploration of Electro-Infiltrated Magnetic Nanocomposites
Başlık:
Exploration of Electro-Infiltrated Magnetic Nanocomposites
Yazar:
Wen, Xiao, author.
ISBN:
9780438122321
Yazar Ek Girişi:
Fiziksel Tanımlama:
1 electronic resource (122 pages)
Genel Not:
Source: Dissertation Abstracts International, Volume: 79-11(E), Section: B.
Advisors: David P. Arnold.
Özet:
This dissertation introduces a scalable and process-integrable manufacturing method, electro-infiltration, for creating microstructures of magnetic nanocomposite materials. Magnetic nanomaterials are first consolidated into a photoresist mold and then a magnetic metal matrix is electroplated to bind the nanomaterials and form a dense nanocomposite microstructure. The magnetic moments in the inclusion phase and the matrix phase can interact through the interfaces by exchange coupling. The nanoscale dimensions and the large interfacial surface area combine to yield hybrid magnetic properties that differ from the constituent phases. Compared to the conventional magnetic materials, the exchange-coupled nanocomposites show promise to provide tunable and improved magnetic properties, such as a higher maximum energy density, low eddy current loss and extended operational frequencies. The electro-infiltration process enables fabrication of nanocomposites more rapidly than the vapor deposition methods, making it efficient and cost-effective to fabricate tens-of-microns-thick films.
Electro-infiltrated gamma-Fe2O3/Fe-Co and Ni 0.5Zn0.5Fe2O4/Ni-Fe nanocomposites are studied for potential application as high performance microinductor cores operating at hundreds of megahertz. In order to reduce the eddy current loss, high-resistivity gamma-Fe2O3 and Ni0.5Zn 0.5Fe2O4 nanoparticles are embedded into soft magnetic Fe-Co or Ni-Fe matrices to form the nanocomposite material. The Ni 0.5Zn0.5Fe2O4/Ni-Fe nanocomposite exhibits a high saturation magnetization of 1.15 T, a coercivity of 250 A/m and a relative permeability of 320 up to 93 MHz, indicating the promising potential of the electro-infiltrated nanocomposites. The peak value of imaginary part of the permeability decreases in nanocomposites, implying energy loss reduction. The gamma-Fe2O3/Fe-Co nanocomposite exhibits a 5x improvement on the product of permeability and cutoff frequency over the Fe-Co film.
Exchange-coupled Fe-Co/CoPt nanocomposites are developed to explore the capacity of forming high energy density permanent magnet using electro-infiltration. The Fe-Co nanoparticles with high magnetization embedded in and magnetically coupled to the hard magnetic CoPt matrix results in an exchange coupled magnet. The nanocomposite yields a saturation magnetization of 0.97 T, a remanent magnetization of 0.70 T and a coercivity of 127 kA/m. However, the maximum energy density of the nanocomposite is 21.8 kJ/m3, which is slightly lower than that of single phase CoPt. As the exchange coupling between the soft phase and the hard phase is manifested in the deltaM and FORC diagram. The improvement on maximum energy density is highly possible in optimized nanocomposite materials.
The developed electro-infiltration process provides a platform to fabricate nano-composite materials. It allows to customize and optimize the material properties of nanocomposites, and offers a new way to explore novel functions of nanocomposite materials.
Notlar:
School code: 0070
Tüzel Kişi Ek Girişi:
Mevcut:*
Yer Numarası | Demirbaş Numarası | Shelf Location | Lokasyon / Statüsü / İade Tarihi |
---|---|---|---|
XX(696661.1) | 696661-1001 | Proquest E-Tez Koleksiyonu | Arıyor... |
On Order
Liste seç
Bunu varsayılan liste yap.
Öğeler başarıyla eklendi
Öğeler eklenirken hata oldu. Lütfen tekrar deneyiniz.
:
Select An Item
Data usage warning: You will receive one text message for each title you selected.
Standard text messaging rates apply.