Author: Wei Cao
Publisher:
ISBN:
Category :
Languages : en
Pages : 284
Book Description
Magnetic Properties and Microstructures of Ni80Fe20/CoxNi1-xO Exchange Coupled Thin Films
Magnetic Properties of Coupled Magnetic Thin Films
Microstructure and Magnetic Properties of Co-(CoO, CoNiO̳2, NiO) and CoxN̳i̳1̳-x̳-CoO Nanocomposite Thin Films
Author: Jae-Young Yi
Publisher:
ISBN:
Category : Anisotropy
Languages : en
Pages : 414
Book Description
Publisher:
ISBN:
Category : Anisotropy
Languages : en
Pages : 414
Book Description
Static and Dynamic Magnetic Properties of Exchange Coupled Thin Film Systems
Magnetic Exchange Coupling in Hard-soft Ferromagnetic Composite Thin Films of CoPt-Co
Author: Jihwan Kim
Publisher:
ISBN:
Category : Ferromagnetic materials
Languages : en
Pages : 480
Book Description
The study of magnetic exchange coupling in nanocomposites of magnetically-hard phases combined with magnetically-soft phases is important for the development of high-performance permanent magnets. The present work aimed to elucidate the microstructure-exchange coupling relationship in model hard/soft bilayers of CoPt(L10, hard)/Co(soft) in both the as-deposited and annealed states. The CoPt layer (25--100 nm) was deposited at room temperature and annealed at 700°C to develop the magnetically hard, ordered L1 0 structure prior to room-temperature deposition of Co (2.8--225 nm). The transformation from FCC to L10 in CoPt was accompanied by grain growth and evolution of a & lang;111 & rang; fiber texture. The L1 0 mean domain area reached approximately one sixth of the mean grain area in nearly-fully and fully ordered CoPt. The coercivity of CoPt and the contribution of a pinning-type mechanism to the coercivity increased with increasing annealing time, concurrent with the increase in L10 fraction. In CoPt/Co bilayers, Co exhibited a & lang;0001 & rang; fiber texture. For as-deposited bilayers, the exchange length of Co was close to the magnetic domain wall width for CoPt. Annealing the bilayers at 300--450°C resulted in minor microstructural changes, increased the extent or strength of coupling and thereby enhanced the reversal coherency of the bilayers such that a Co layer of twice the CoPt domain wall width was fully coupled to the CoPt. Note that in bilayers with robust coupling both phases are affected, i.e., the magnetically-hard phase is exchange-softened, while the magnetically-soft phase is exchange-hardened. In contrast to lower-temperature anneals, annealing at 500--550°C, or for extended periods at 450°C, resulted in interdiffusion of Co and CoPt, consumption of the latter and formation of two new FCC and HCP Co-Pt solid solutions. These interdiffused bilayers showed an increased reversal coherency and a highly developed out-of-film plane anisotropy. When the magnetic and microstructural data are considered together, this study shows that the properties of hard/soft nanocomposites depend not only on the dimensions of both phases, but also on the physical and magnetic characteristics of each phase. A most significant outcome of this work is the demonstration that exchange coupling may be altered, and perhaps tailored, by processing-induced changes in the interphase interface.
Publisher:
ISBN:
Category : Ferromagnetic materials
Languages : en
Pages : 480
Book Description
The study of magnetic exchange coupling in nanocomposites of magnetically-hard phases combined with magnetically-soft phases is important for the development of high-performance permanent magnets. The present work aimed to elucidate the microstructure-exchange coupling relationship in model hard/soft bilayers of CoPt(L10, hard)/Co(soft) in both the as-deposited and annealed states. The CoPt layer (25--100 nm) was deposited at room temperature and annealed at 700°C to develop the magnetically hard, ordered L1 0 structure prior to room-temperature deposition of Co (2.8--225 nm). The transformation from FCC to L10 in CoPt was accompanied by grain growth and evolution of a & lang;111 & rang; fiber texture. The L1 0 mean domain area reached approximately one sixth of the mean grain area in nearly-fully and fully ordered CoPt. The coercivity of CoPt and the contribution of a pinning-type mechanism to the coercivity increased with increasing annealing time, concurrent with the increase in L10 fraction. In CoPt/Co bilayers, Co exhibited a & lang;0001 & rang; fiber texture. For as-deposited bilayers, the exchange length of Co was close to the magnetic domain wall width for CoPt. Annealing the bilayers at 300--450°C resulted in minor microstructural changes, increased the extent or strength of coupling and thereby enhanced the reversal coherency of the bilayers such that a Co layer of twice the CoPt domain wall width was fully coupled to the CoPt. Note that in bilayers with robust coupling both phases are affected, i.e., the magnetically-hard phase is exchange-softened, while the magnetically-soft phase is exchange-hardened. In contrast to lower-temperature anneals, annealing at 500--550°C, or for extended periods at 450°C, resulted in interdiffusion of Co and CoPt, consumption of the latter and formation of two new FCC and HCP Co-Pt solid solutions. These interdiffused bilayers showed an increased reversal coherency and a highly developed out-of-film plane anisotropy. When the magnetic and microstructural data are considered together, this study shows that the properties of hard/soft nanocomposites depend not only on the dimensions of both phases, but also on the physical and magnetic characteristics of each phase. A most significant outcome of this work is the demonstration that exchange coupling may be altered, and perhaps tailored, by processing-induced changes in the interphase interface.
Microstructure and Magnetic Properties of Co-CoO Nanocomposite Films
Author: Jae Y. Yi
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
The effect of exchange anisotropy on nanosize Co particles was studied in Co-CoO nanocomposite thin films for possible applications for magnetic storage media. XRD analyses showed nanosize hcp Co particles and (111) textured CoO phase. A broken columnar structure was observed in cross-section TEM images. Very large room temperature coercivity (^ 1 kOe) was observed and believed to be doe to a shape effect and possible local exchange coupling. Large exchange anisotropy at low temperatures and linear type temperature dependence were explained by finite size effects and thermal relaxation of the CoO particles. A slow decrease of thermoremanent moment (TRM) with temperature and large TRM at room temperature indicated that the exchange anisotropy significantly modified the anisotropy energy barrier of the Co crystallites in the CoO matrix. The results indicated that the exchange anisotropy could be used to stabilize nanosize ferromagnetic particles.
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
The effect of exchange anisotropy on nanosize Co particles was studied in Co-CoO nanocomposite thin films for possible applications for magnetic storage media. XRD analyses showed nanosize hcp Co particles and (111) textured CoO phase. A broken columnar structure was observed in cross-section TEM images. Very large room temperature coercivity (^ 1 kOe) was observed and believed to be doe to a shape effect and possible local exchange coupling. Large exchange anisotropy at low temperatures and linear type temperature dependence were explained by finite size effects and thermal relaxation of the CoO particles. A slow decrease of thermoremanent moment (TRM) with temperature and large TRM at room temperature indicated that the exchange anisotropy significantly modified the anisotropy energy barrier of the Co crystallites in the CoO matrix. The results indicated that the exchange anisotropy could be used to stabilize nanosize ferromagnetic particles.
Microstructure and Magnetic Properties of FePt/MgO Multilayered Thin Films
Author: Yang Fu
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 71
Book Description
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 71
Book Description
2015 Ieee International Magnetics Conference (Intermag)
Author: IEEE Staff
Publisher:
ISBN: 9781479973231
Category :
Languages : en
Pages :
Book Description
INTERMAG is the premier conference on all aspects of applied magnetism, and all members of the international scientific communities interested in new developments in magnetism and associated technologies are invited to attend and submit their latest findings
Publisher:
ISBN: 9781479973231
Category :
Languages : en
Pages :
Book Description
INTERMAG is the premier conference on all aspects of applied magnetism, and all members of the international scientific communities interested in new developments in magnetism and associated technologies are invited to attend and submit their latest findings
Cluster Assembled Materials
Author: Klaus Sattler
Publisher: CRC Press
ISBN: 9780878497478
Category : Technology & Engineering
Languages : en
Pages : 318
Book Description
It is now some 15 years since atomic clusters were first produced and investigated in laboratories. Since then, knowledge concerning clusters has enjoyed rapid and sustained growth, and cluster research has become a new branch of science.
Publisher: CRC Press
ISBN: 9780878497478
Category : Technology & Engineering
Languages : en
Pages : 318
Book Description
It is now some 15 years since atomic clusters were first produced and investigated in laboratories. Since then, knowledge concerning clusters has enjoyed rapid and sustained growth, and cluster research has become a new branch of science.
Magnetic Nanostructures
Author: Hari Singh Nalwa
Publisher:
ISBN: 9781588830005
Category : Science
Languages : en
Pages : 0
Book Description
Twelve contributions comprise a reference source that is a coherent presentation of the state of the art in this fast growing area of nanotechnology research. Magnetic nanostructures are important for their phenomenal potential for storage; their great commercial value will come from applications in
Publisher:
ISBN: 9781588830005
Category : Science
Languages : en
Pages : 0
Book Description
Twelve contributions comprise a reference source that is a coherent presentation of the state of the art in this fast growing area of nanotechnology research. Magnetic nanostructures are important for their phenomenal potential for storage; their great commercial value will come from applications in