Magnetic domain reversal in ultrathin Co(001) films probed by giant magnetoresistance measurements

2000 ◽  
Vol 61 (10) ◽  
pp. 6871-6875 ◽  
Author(s):  
S. P. Li ◽  
A. Samad ◽  
W. S. Lew ◽  
Y. B. Xu ◽  
J. A. C. Bland
Keyword(s):  
Giant Magnetoresistance ◽  
Magnetic Domain ◽  
Domain Reversal

Introduction of spin torques

2017 ◽  
Author(s):  
T. Kimura
Keyword(s):  
Angular Momentum ◽  
Giant Magnetoresistance ◽  
Spontaneous Magnetization ◽  
Magnetic Domain ◽  
Magnetic Multilayers ◽  
Transfer Effect ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Spin Angular Momentum ◽  
Spin Torques

This chapter discusses the spin-transfer effect, which is described as the transfer of the spin angular momentum between the conduction electrons and the magnetization of the ferromagnet that occurs due to the conservation of the spin angular momentum. L. Berger, who introduced the concept in 1984, considered the exchange interaction between the conduction electron and the localized magnetic moment, and predicted that a magnetic domain wall can be moved by flowing the spin current. The spin-transfer effect was brought into the limelight by the progress in microfabrication techniques and the discovery of the giant magnetoresistance effect in magnetic multilayers. Berger, at the same time, separately studied the spin-transfer torque in a system similar to Slonczewski’s magnetic multilayered system and predicted spontaneous magnetization precession.

Sub-200 Oe Giant Magnetoresistance in Manganite Tunnel Junctions

1997 ◽  
Vol 494 ◽  
Author(s):  
Gang Xiao ◽  
A. Gupta ◽  
X. W. Li ◽  
G. Q. Gong ◽  
J. Z. Sun
Keyword(s):  
Electronic Structure ◽  
Colossal Magnetoresistance ◽  
Giant Magnetoresistance ◽  
Domain Walls ◽  
Tunnel Junctions ◽  
Research Effort ◽  
Boundary Effect ◽  
Magnetic Domain ◽  
Magnetic Ordering ◽  
Dependent Transport

ABSTRACTMetallic manganite oxides, La1-xDxMnO3 (D=Sr, Ca, etc.), display “colossal” magnetoresistance (CMR) near their magnetic phase transition temperatures (Tc) when subject to a Tesla-scale magnetic field. This phenomenal effect is the result of the strong interplay inherent in this class of materials among electronic structure, magnetic ordering, and lattice dynamics. Though fundamentally interesting, the CMR effect achieved only at large fields poses severe technological challenges to potential applications in magnetoelectronic devices, where low field sensitivity is crucial. Among the objectives of our research effort involving manganite materials is to reduce the field scale of MR by designing and fabricating tunnel junctions and other structures rich in magnetic domain walls. The junction electrodes were made of doped manganite epitaxial films, and the insulating barrier of SrTiO3. The interfacial expitaxy has been imaged by using high-resolution transmission electron microscopy (TEM). We have used self-aligned lithographic process to pattern the junctions to micron scale in size. Large MR values close to 250% at low fields of a few tens of Oe have been observed. The mechanism of the spin-dependent transport is due to the spin-polarized tunneling between the half-metallic electrodes, in which the spins of the conduction electrons are nearly fully polarized. We will present results of field and temperature dependence of MR in these structures and discuss the electronic structure of the manganite inferred from tunneling measurement. Results of large MR at low fields due to the grain-boundary effect will also be presented.

Magnetic domain structures and giant magnetoresistance of granular (Ni[sub 74]Fe[sub 16]Co[sub 10])[sub 35]Ag[sub 65] films

2000 ◽  
Vol 88 (7) ◽  
pp. 4216 ◽  
Author(s):  
H. Wang ◽  
X. Lu ◽  
X. Yan ◽  
S. P. Wong ◽  
W. Y. Cheung ◽  
...  
Keyword(s):  
Giant Magnetoresistance ◽  
Magnetic Domain ◽  
Domain Structures

Magnetic domain reversal behavior for various patterned hole depths

2005 ◽  
Vol 41 (2) ◽  
pp. 950-952 ◽  
Author(s):  
Te-Ho Wu ◽  
L.X. Ye ◽  
Chun-Shin Yeh ◽  
Y.W. Huang ◽  
Bohr-Ran Huang ◽  
...  
Keyword(s):  
Magnetic Domain ◽  
Domain Reversal

In-situ TEM studies of magnetization reversal processes in magnetic nanostructures

2005 ◽  
Vol 907 ◽  
Author(s):  
Amanda K Petford-Long ◽  
Thomas Bromwich ◽  
Amit Kohn ◽  
Victoria Jackson ◽  
Takeshi Kasama ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetization Reversal ◽  
Giant Magnetoresistance ◽  
Magnetic Nanostructures ◽  
Magnetic Domain ◽  
Ferromagnetic Material ◽  
In Situ Tem ◽  
Transmission Electron

AbstractOne of the most widely studied types of magnetic nanostructure is that used in devices based on the giant magnetoresistance (GMR) or tunnel magnetoresistance (TMR) phenomena. In order to understand the behaviour of these materials it is important to be able to follow their magnetisation reversal mechanism, and one of the techniques enabling micromagnetic studies at the sub-micron scale is transmission electron microscopy. Two techniques can be used: Lorentz transmission electron microscopy and off-axis electron holography, both of which allow the magnetic domain structure of a ferromagnetic material to be investigated dynamically in real-time with a resolution of a few nanometres. These techniques have been used in combination with in situ magnetizing experiments, to carry out qualitative and quantitative studies of magnetization reversal in a range of materials including spin-tunnel junctions, patterned thin film elements and magnetic antidot arrays. Quantitative analysis of the Lorentz TEM data has been carried out using the transport of intensity equation (TIE) approach.

Magnetic domain reversal induced by thermal activation in SmCo alloy

2021 ◽  
pp. 162684
Author(s):  
Zhihe Zhao ◽  
Jiangtao Zhao ◽  
Mingkun Wang ◽  
Weixing Xia ◽  
Zhenlong Chao ◽  
...  
Keyword(s):  
Thermal Activation ◽  
Magnetic Domain ◽  
Domain Reversal

Analysis Interaction Field Strength and Spectrum from Microhysteresis Loops

2007 ◽  
Vol 998 ◽  
Author(s):  
Lin-Xiu Ye ◽  
Jia-Mou Lee ◽  
Te-ho Wu
Keyword(s):  
Experimental Data ◽  
Field Strength ◽  
Direct Method ◽  
Magnetic Domain ◽  
Magnetic Thin Films ◽  
Interaction Field ◽  
Field Distributions ◽  
Reversal Mechanism ◽  
A Direct Method ◽  
Domain Reversal

ABSTRACTIn this paper, we present a direct method to analyze the mechanism of magnetic domain reversal for a series of amorphous Dyx(FeCo)1-x magnetic thin films and whereby we obtained the distributions of the coercivities and interaction fields from 90,000 measurements of the microhysteresis loops. The standard deviations of the coercivity and the interaction field distributions, σi and σk, can be estimated by fitting the experimental data with the Gaussian- Preisach function. The results show that the interaction field decreases as Dy composition approaches the compensation point. The reversal mechanism is dominated by nucleation when σi is smaller than σk. The relationships between the magnetization reversal and interaction field strength are discussed

scholarly journals 100-nm-sized magnetic domain reversal by the magneto-electric effect in self-assembled BiFeO3/CoFe2O4 bilayer films

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Keita Sone ◽  
Hiroshi Naganuma ◽  
Masaki Ito ◽  
Takamichi Miyazaki ◽  
Takashi Nakajima ◽  
...  
Keyword(s):  
Magnetic Domain ◽  
Bilayer Films ◽  
Self Assembled ◽  
Electric Effect ◽  
Domain Reversal

Magnetic domain reversal dynamics in Co/Pd nanomultilayers

2000 ◽  
Vol 209 (1-3) ◽  
pp. 84-89 ◽  
Author(s):  
Sug-Bong Choe ◽  
Sung-Chul Shin
Keyword(s):  
Magnetic Domain ◽  
Domain Reversal
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