scholarly journals Ultrasensitive detection enabled by nonlinear magnetization of nanomagnetic labels

Nanoscale ◽  
2018 ◽  
Vol 10 (24) ◽  
pp. 11642-11650 ◽  
Author(s):  
M. P. Nikitin ◽  
A. V. Orlov ◽  
I. L. Sokolov ◽  
A. A. Minakov ◽  
P. I. Nikitin ◽  
...  
Keyword(s):  
Single Domain ◽  
Ultrasensitive Detection ◽  
Strong Nonlinearity ◽  
Magnetization Process ◽  
High Background ◽  
Domain Configuration ◽  
Spin Vortex ◽  
Soft Disk ◽  
Nonlinear Magnetization

The magnetically soft, disk-shaped particles reveal a strong nonlinearity of the magnetization process due to irreversible transitions from the spin vortex to single-domain configuration, enabling their ultrasensitive detection in high-background environments.

Introduction of Fine Engineered Domain Configuration into Potassium Niobate Single Crystals

2007 ◽  
Vol 350 ◽  
pp. 89-92
Author(s):  
Keisuke Yokoh ◽  
Tomomitsu Muraishi ◽  
Song Min Nam ◽  
Hirofumi Kakemoto ◽  
Takaaki Tsurumi ◽  
...  
Keyword(s):  
Electric Field ◽  
Single Crystals ◽  
Room Temperature ◽  
Single Domain ◽  
Potassium Niobate ◽  
Field Exposure ◽  
Domain State ◽  
Domain Configuration ◽  
Dc Electric Field ◽  
Direction Of Polarization

To induce fine engineered domain configurations into potassium niobate (KNbO3) single crystals, two kinds of methods were performed, i.e., (1) high DC electric field exposure along the opposite direction of polarization of KNbO3 single-domain crystals at room temperature, and (2) introduction of randomly oriented fine domain configuration by heat treatment at 700 °C and then high DC electric field exposure along [001]c direction of KNbO3 multidomain crystals at room temperature. When the method (1) was performed, finally, the poled KNbO3 crystals became to single-domain state again through the formation of multidomain state. On the other hand, the KNbO3 multidomain crystals were obtained by using the method (2), and an enhancement of piezoelectric-related properties was observed.

scholarly journals MODELLING OF SPINTRONIC DEVICES FOR APPLICATION IN RANDOM ACCESS MEMORY

2020 ◽  
Vol 10 (1) ◽  
pp. 62-65
Author(s):  
Ruslan Politanskyi ◽  
Maria Vistak ◽  
Andriy Veryga ◽  
Tetyana Ruda
Keyword(s):  
Error Probability ◽  
High Speed ◽  
Scientific Research ◽  
Single Domain ◽  
Memory Devices ◽  
Magnetization Process ◽  
Recording Time ◽  
Bit Error Probability ◽  
Recording Process ◽  
Wide Range

The article analyzes the physical processes that occur in spin-valve structures during recording process which occurs in high-speed magnetic memory devices. Considered are devices using magnetization of the ferromagnetic layer through transmitting magnetic moment by polarized spin (STT-MRAM). Basic equations are derived to model the information recording process in the model of symmetric binary channel. Because the error probability arises from the magnetization process, a model of the magnetization process is formed, which is derived from the Landau-Lifshitz-Gilbert equations under the assumption of a single-domain magnet. The choice of a single-domain model is due to the nanometer size of the flat magnetic layer. The developed method of modeling the recording process determines the dependence of such characteristics as the bit error probability and the rate of recording on two important technological characteristics of the recording process: the value of the current and its duration. The end result and the aim of the simulation is to determine the optimal values of the current and its duration at which the speed of the recording process is the highest for a given level of error probability. The numerical values of the transmission rate and error probability were obtained for a wide range of current values (10–1500 μA) and recording time of one bit (1–70 ns), and generally correctly describe the process of information transmission. The calculated data were compared with the technical characteristics of existing industrial devices and devices which are the object of the scientific research. The resulting model can be used to simulate devices using different values of recording currents: STT-MRAM series chips using low current values (500-100 μA), devices in the stage of technological design and using medium current values (100–500 μA) and devices that are the object of experimental scientific research and use high currents (500–1000 μA). The model can also be applied to simulate devices with different data rates, which have different requirements for both transmission speed and bit error probability. In this way, the model can be applied to both high-speed memory devices in computer systems and signal sensors, which are connected to sensor networks or connected to the IoT.

Evidence of Single-Domain Magnetite in the Michikamau Anorthosite

1971 ◽  
Vol 8 (3) ◽  
pp. 361-370 ◽  
Author(s):  
G. S. Murthy ◽  
M. E. Evans ◽  
D. I. Gough
Keyword(s):  
Remanent Magnetization ◽  
Theoretical Models ◽  
Natural Remanent Magnetization ◽  
Single Domain ◽  
Isothermal Remanent Magnetization ◽  
Mineral Separation ◽  
Domain Configuration ◽  
Plagioclase Felspar ◽  
Magnetite Particles ◽  
Theoretical Evidence

The Michikamau anorthosite possesses very stable natural remanent magnetization, some of which resists alternating fields up to 1800 Oe. The rock contains two types of opaque grains, fine opaque needles of order 10 × 0.5 μ in the plagioclase felspar, and large equidimensional magnetite particles. Ore microscope studies suggest, but do not establish, that the needles are composed of magnetite. Saturation isothermal remanence and thermal demagnetization studies indicate magnetite as the carrier of remanent magnetization. In order to distinguish the effects of the large grains from those of the needles, mineral separation was used to show that an artificial specimen of essentially pure plagioclase had very similar isothermal remanent magnetization properties to the whole rock. Both indicated magnetite as the magnetic mineral. Thermoremanent properties of the separated mineral fractions indicated magnetite as the dominant magnetic constituent but showed some evidence of laboratory-produced hematite. Theoretical models of grains elongated along [111] and [110] axes are used to show that magnetite needles can exist in stable single-domain configuration in the size and shape ranges of the needles observed in the Michikamau anorthosite. There is thus considerable experimental and theoretical evidence for the conclusion that the stable remanent magnetization of the Michikamau anorthosite is carried by fine single–domain needles of magnetite in the plagioclase felspar.

Ultrasensitive Detection of Ricin Toxin in Multiple Sample Matrixes Using Single-Domain Antibodies

2015 ◽  
Vol 87 (13) ◽  
pp. 6570-6577 ◽  
Author(s):  
Shonda T. Gaylord ◽  
Trinh L. Dinh ◽  
Ellen R. Goldman ◽  
George P. Anderson ◽  
Kevin C. Ngan ◽  
...  
Keyword(s):  
Single Domain ◽  
Ultrasensitive Detection ◽  
Ricin Toxin ◽  
Multiple Sample ◽  
Single Domain Antibodies

Nonlinear Magnetization Process of Single-Crystalline FeSi

2000 ◽  
Vol 69 (1) ◽  
pp. 219-224 ◽  
Author(s):  
Keiichi Koyama ◽  
Tsuneaki Goto ◽  
Takeshi Kanomata ◽  
Ryunosuke Note ◽  
Yoshinori Takahashi
Keyword(s):  
Magnetization Process ◽  
Single Crystalline ◽  
Nonlinear Magnetization

Enhanced Photocatalytic Activity by the Combined Influence of Ferroelectric Domain and Au Nanoparticles for BaTiO3 Fibers

NANO ◽  
2018 ◽  
Vol 13 (12) ◽  
pp. 1850149 ◽  
Author(s):  
Xiaoshan Zhang ◽  
Yu Huan ◽  
Yuanna Zhu ◽  
Hui Tian ◽  
Kai Li ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Surface Plasmon Resonance ◽  
Electric Field ◽  
Photocatalytic Performance ◽  
Au Nanoparticles ◽  
Ferroelectric Domain ◽  
Single Domain ◽  
Internal Electric Field ◽  
Domain Configuration ◽  
And Migration

Ferroelectric particles have been applied in the photocatalytic field because the spontaneous polarization results in the internal electric field, which can accelerate the separation and migration of photogenerated carriers. In this study, the BaTiO3 (BT) fibers are synthesized by electrospinning. The BT fibers calcined above 800[Formula: see text]C exhibit a strong ferroelectric property, which is verified by a typical butterfly-shaped displacement-voltage loop. It is found that the BT fibers with the single-domain structure exhibit better photocatalytic performance than that with the multi-domain configuration. When the single-domain transforms into multi-domain, the integrated internal electric field correspondingly breaks up, inducing that the internal electric field might cancel each other out and diminish the separation of photogenerated carriers. Also, the Au nanoparticles can improve the photocatalytic activity further on account of the surface plasmon resonance. Therefore, it is suggested that Au nanoparticles decorated on ferroelectric BT nanomaterials are promising photocatalysts.

Scattering-angle dependence of signal/background ratio of inner-shell electron excitation loss in EELS

1983 ◽  
Vol 41 ◽  
pp. 390-391
Author(s):  
T. Oikawa ◽  
M. Inoue ◽  
T. Honda ◽  
Y. Kokubo
Keyword(s):  
Energy Loss ◽  
Electron Excitation ◽  
Heavy Elements ◽  
Background Intensity ◽  
Light Elements ◽  
Energy Analyzer ◽  
High Background ◽  
Scattering Angle ◽  
Angle Dependence ◽  
Shell Electron

EELS allows us to make analysis of light elements such as hydrogen to heavy elements of microareas on the specimen. In energy loss spectra, however, elemental signals ride on a high background; therefore, the signal/background (S/B) ratio is very low in EELS. A technique which collects the center beam axial-symmetrically in the scattering angle is generally used to obtain high total intensity. However, the technique collects high background intensity together with elemental signals; therefore, the technique does not improve the S/B ratio. This report presents the experimental results of the S/B ratio measured as a function of the scattering angle and shows the possibility of the S/B ratio being improved in the high scattering angle range.Energy loss spectra have been measured using a JEM-200CX TEM with an energy analyzer ASEA3 at 200 kV.Fig.l shows a typical K-shell electron excitation edge riding on background in an energy loss spectrum.

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