Positive Domain-Wall Magnetoresistance of Ferromagnetic Point Contacts

2001 ◽  
pp. 197-201
Author(s):  
J. Caro ◽  
S. J. C. H. Theeuwen ◽  
K. I. Schreurs ◽  
R. P. Gorkom ◽  
K. P. Wellock ◽  
...  
Keyword(s):  
Domain Wall ◽  
Point Contacts

Effect of the quantum domain wall on conductance quantization and magnetoresistance in magnetic point contacts

2001 ◽  
Vol 84 (1-2) ◽  
pp. 107-113 ◽  
Author(s):  
Hiroshi Imamura ◽  
Nobuhiko Kobayashi ◽  
Saburo Takahashi ◽  
Sadamichi Maekawa
Keyword(s):  
Domain Wall ◽  
Point Contacts ◽  
Conductance Quantization ◽  
Quantum Domain

Structure-related effects on the domain wall migration in atomic point contacts

2007 ◽  
Vol 316 (2) ◽  
pp. e934-e936
Author(s):  
Maria Stamenova ◽  
Sudhakar Sahoo ◽  
Tchavdar N. Todorov ◽  
Stefano Sanvito
Keyword(s):  
Domain Wall ◽  
Point Contacts ◽  
Atomic Point Contacts

Electron Microscopy of Graphite Intercalation Compounds

1982 ◽  
Vol 40 ◽  
pp. 544-545
Author(s):  
G. Timp ◽  
L. Salamanca-Riba ◽  
L.W. Hobbs ◽  
G. Dresselhaus ◽  
M.S. Dresselhaus
Keyword(s):  
Electron Microscopy ◽  
Phase Transitions ◽  
Domain Wall ◽  
Intercalation Compounds ◽  
Lattice Plane ◽  
Wall Model ◽  
Graphite Intercalation Compounds ◽  
Fundamental Symmetry ◽  
Graphite Intercalation

Electron microscopy can be used to study structures and phase transitions occurring in graphite intercalations compounds. The fundamental symmetry in graphite intercalation compounds is the staging periodicity whereby each intercalate layer is separated by n graphite layers, n denoting the stage index. The currently accepted model for intercalation proposed by Herold and Daumas assumes that the sample contains equal amounts of intercalant between any two graphite layers and staged regions are confined to domains. Specifically, in a stage 2 compound, the Herold-Daumas domain wall model predicts a pleated lattice plane structure.

The direct determination of magnetic domain wall profiles using a split detector STEM

1978 ◽  
Vol 36 (1) ◽  
pp. 466-467
Author(s):  
J.N. Chapman ◽  
P.E. Batson ◽  
E.M. Waddell ◽  
R.P. Ferrier
Keyword(s):  
Electron Microscope ◽  
Domain Wall ◽  
Transmission Electron Microscope ◽  
Domain Walls ◽  
Photographic Plate ◽  
Magnetic Domain ◽  
Direct Determination ◽  
Quantitative Information ◽  
Scanning Transmission Electron Microscope ◽  
Transmission Electron

By far the most commonly used mode of Lorentz microscopy in the examination of ferromagnetic thin films is the Fresnel or defocus mode. Use of this mode in the conventional transmission electron microscope (CTEM) is straightforward and immediately reveals the existence of all domain walls present. However, if such quantitative information as the domain wall profile is required, the technique suffers from several disadvantages. These include the inability to directly observe fine image detail on the viewing screen because of the stringent illumination coherence requirements, the difficulty of accurately translating part of a photographic plate into quantitative electron intensity data, and, perhaps most severe, the difficulty of interpreting this data. One solution to the first-named problem is to use a CTEM equipped with a field emission gun (FEG) (Inoue, Harada and Yamamoto 1977) whilst a second is to use the equivalent mode of image formation in a scanning transmission electron microscope (STEM) (Chapman, Batson, Waddell, Ferrier and Craven 1977), a technique which largely overcomes the second-named problem as well.

The need of electron microscopy in the study of domains and domain walls in ferroelectrics

1994 ◽  
Vol 52 ◽  
pp. 550-551
Author(s):  
Wenwu Cao
Keyword(s):  
Domain Wall ◽  
Domain Walls ◽  
High Mobility ◽  
Continuum Theory ◽  
Polarization Vector ◽  
Ferroelectric Materials ◽  
Dielectric Constants ◽  
Nonlocal Coupling ◽  
Cubic Symmetry ◽  
Gradient Energy

Domain structures play a key role in determining the physical properties of ferroelectric materials. The formation of these ferroelectric domains and domain walls are determined by the intrinsic nonlinearity and the nonlocal coupling of the polarization. Analogous to soliton excitations, domain walls can have high mobility when the domain wall energy is high. The domain wall can be describes by a continuum theory owning to the long range nature of the dipole-dipole interactions in ferroelectrics. The simplest form for the Landau energy is the so called ϕ model which can be used to describe a second order phase transition from a cubic prototype,where Pi (i =1, 2, 3) are the components of polarization vector, α's are the linear and nonlinear dielectric constants. In order to take into account the nonlocal coupling, a gradient energy should be included, for cubic symmetry the gradient energy is given by,

Some peculiarities of 180°-domain wall moticn in thin ferroelectric crystals

1983 ◽  
Vol 44 (10) ◽  
pp. 293-299 ◽  
Author(s):  
E. V. Burtsev ◽  
S. Y. Chervonobrodov
Keyword(s):  
Domain Wall ◽  
Ferroelectric Crystals

Different Transmission Regimes of Two Quantum Point Contacts in a Magnetic Field

1995 ◽  
Vol 5 (9) ◽  
pp. 1257-1262
Author(s):  
V. Marigliano Ramaglia ◽  
F. Ventriglia ◽  
G. P. Zucchelli
Keyword(s):  
Magnetic Field ◽  
Quantum Point Contacts ◽  
Point Contacts ◽  
Quantum Point

Numerical Analysis of a Magnetic Domain Wall in a Magnetic Nanocontact

2005 ◽  
Vol 29 (2) ◽  
pp. 116-119
Author(s):  
T. Komine ◽  
T. Takahashi ◽  
R. Sugita ◽  
T. Muranoi ◽  
Y. Hasegawa
Keyword(s):  
Numerical Analysis ◽  
Domain Wall ◽  
Magnetic Domain ◽  
Magnetic Domain Wall

Magnetization dynamics of irradiation-fabricated perpendicularly magnetized dots inside a softer magnetic matrix

2003 ◽  
Vol 777 ◽  
Author(s):  
T. Devolder ◽  
M. Belmeguenai ◽  
C. Chappert ◽  
H. Bernas ◽  
Y. Suzuki
Keyword(s):  
Domain Wall ◽  
Magnetic Anisotropy ◽  
Magnetization Reversal ◽  
Ion Irradiation ◽  
Magnetic Nanostructures ◽  
Magnetic Storage ◽  
Exchange Field ◽  
Static Magnetization ◽  
Specific Domain ◽  
Helium Ion

AbstractGlobal Helium ion irradiation can tune the magnetic properties of thin films, notably their magneto-crystalline anisotropy. Helium ion irradiation through nanofabricated masks can been used to produce sub-micron planar magnetic nanostructures of various types. Among these, perpendicularly magnetized dots in a matrix of weaker magnetic anisotropy are of special interest because their quasi-static magnetization reversal is nucleation-free and proceeds by a very specific domain wall injection from the magnetically “soft” matrix, which acts as a domain wall reservoir for the “hard” dot. This guarantees a remarkably weak coercivity dispersion. This new type of irradiation-fabricated magnetic device can also be designed to achieve high magnetic switching speeds, typically below 100 ps at a moderate applied field cost. The speed is obtained through the use of a very high effective magnetic field, and high resulting precession frequencies. During magnetization reversal, the effective field incorporates a significant exchange field, storing energy in the form of a domain wall surrounding a high magnetic anisotropy nanostructure's region of interest. The exchange field accelerates the reversal and lowers the cost in reversal field. Promising applications to magnetic storage are anticipated.

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