Magnetism of Bismuth(III) Oxide-Based Compounds

2015 ◽  
Vol 233-234 ◽  
pp. 113-116
Author(s):  
Eleonora A. Kravchenko
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Spin Dynamics ◽  
Spin Echo ◽  
Magnetic Moments ◽  
Fold Increase ◽  
Zero Field ◽  
Line Shapes ◽  
Nuclear Magnetic Moments ◽  
Magnetic Splitting

209Bi NQR experiments, including analysis of zero-field line shapes, Zeeman-perturbed patterns and zero-field spin-echo envelopes were made to examine magnetic splitting of resonances revealed in the spectra of Main group element compounds of general composition BakBilAmOn (A=Al, В, Ge, Br, Cl). The results were explained assuming the existence in the compounds of ordered internal magnetic fields from 5 to 250 G which notably exceed those of nuclear magnetic moments. A dramatic (8−10-fold) increase in the resonance intensities, instead of broadening and fading, was observed for such compounds upon applying weak (below 500 Oe) external magnetic fields. The effect was shown to relate to the spin dynamics, namely, to the influence of external magnetic field on the nuclear spin-spin relaxation of the compounds with anomalous magnetic properties. In α-Bi2O3, paramagnetism depending on the thermal prehistory of a sample was found using SQUID-technique; magnetoelectric effect linear in magnetic field was also observed for this oxide.

scholarly journals Reducing the influence of interference of spacecraft magnetic field on magnetic measurements

2019 ◽  
Vol 18 (2) ◽  
pp. 33-40
Author(s):  
A. M. Beznyakov ◽  
I. S. Guriev ◽  
I. P. Ryzhova
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Support Systems ◽  
Magnetic Measurements ◽  
Magnetic Moments ◽  
Navigation Support

The article presents constructive ways of reducing the influence of magnetic interference from spacecraft, due to its own magnetic fields, on the on-board magnetic measurements, as well as reducing the resulting magnetic moments. Well-known methods of removing magnetometer sensors from the locations of the most powerful sources of magnetic fields of a spacecraft, in particular, using extendable booms, are considered. In addition, methods for reducing the influence of spacecraft self- magnetic fields on the onboard magnetometric navigation support systems using known closed and proposed hemispherical ferromagnetic shields are considered

scholarly journals Spin transport and spin dynamics in antiferromagnets

2021 ◽  
Author(s):  
◽  
Geert Hoogeboom
Keyword(s):  
Magnetic Field ◽  
Heavy Metal ◽  
Spin Transport ◽  
Spin Dynamics ◽  
Magnetic Moments ◽  
Spin Current ◽  
Active Role ◽  
Metal Films ◽  
Alternating Direction ◽  
High Processing

Ferromagnets (FMs) have been a key ingredient in information technology because it is easy to manipulate and read out the magnetization. Antiferromagnets (AFMs) have magnetic moments with alternating direction resulting in negligible magnetization. This gives them high processing and device downscaling features, but this also makes it challenging to manipulate and interact with the AFM order. This thesis studies this interaction with antiferromagnets. NiO AFM order has been read out by electrically injecting spin current via the spin Hall effect in thin heavy metal films. In DyFeO3, both Dy and Fe magnetic moments, their excitation and interaction have been probed. A magnetic field lifts the degeneracy of magnetic excitations with opposite magnon spin, allowing a spin current to be detected nonlocally. The AFM order and the generation of spin current can easily be controlled by an adjacent FM. Thereby, we show that AFMs have the potential to play an active role in spintronics.

Equipotential transformation from multipole systems to dipole systems

1987 ◽  
Vol 414 (1847) ◽  
pp. 359-369
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Spherical Harmonic ◽  
Magnetic Moments ◽  
Numerical Comparison ◽  
Magnetic Dipoles ◽  
Planetary Magnetic Fields ◽  
Vector Sum ◽  
Planetary Magnetic Field ◽  
Good Agreement

The paper shows that a planetary magnetic field expressed in the conventional form of a spherical harmonic expanson can be completely represented by the vector sum of fields produced by a set of magnetic dipoles with different magnetic moments, tilted from the planetary spin axis and offset from the planetary centre by different amounts. For convenience, the transformation from multipole systems to dipole systems is restricted to that from multipoles up to octupole to five dipoles. The scalar equipotential transformation analytically results in 24 equations; these can be subsequently solved for the 24 adjustable parameters in dipole systems with the predetermined ‘main dipole’. The numerical comparison of the jovian magnetic field between the jovian O 4 and the five-dipole models reveals a very good agreement with the subtle details. It is obvious that this type of transformation would open up the simplest practical way to simulate planetary magnetic fields with the dipole patterns.

scholarly journals Zeeman NQR Studies on Powdered Bromine Compounds Having Small η

1990 ◽  
Vol 45 (3-4) ◽  
pp. 599-602 ◽  
Author(s):  
Osamu Ege ◽  
Hisao Negita
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Static Magnetic Field ◽  
Bridge Circuit ◽  
Integral Form ◽  
Absorption Lines ◽  
Zero Field ◽  
Line Shapes

Abstract The Zeeman NQR of 79 Br and 81Br in samples having relatively small r\ was studied on several bromine compounds which were in the powder or polycrystal state. The absorption lines were detected in the integral form by the bridge circuit. When a static magnetic field was applied, the line shapes were broadened and usually two dips appeared symmetrically at both sides of the zero field line. The values of η were estimated from the patterns of the dips. For compounds such as NaBrO3 , however, as expected no dips were observed.

scholarly journals On the influence of magnetic fields in neutral planetary wakes

2016 ◽  
Vol 12 (S328) ◽  
pp. 192-197
Author(s):  
C. Villarreal D’Angelo ◽  
M. Schneiter ◽  
A. Esquivel
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Radiation Pressure ◽  
Stellar Wind ◽  
Magnetic Moments ◽  
Radiative Processes ◽  
Planetary Magnetic Fields ◽  
Stellar Magnetic Fields

AbstractWe present a 3D magnetohydrodynamic study of the effect that stellar and planetary magnetic fields have on the calculated Lyα absorption during the planetary transit, employing parameters that resemble the exoplanet HD209458b. We assume a dipolar magnetic field for both the star and the planet, and use the Parker solution to initialize the stellar wind. We also consider the radiative processes and the radiation pressure.We use the numerical MHD code Guacho to run several models varying the values of the planetary and stellar magnetic moments within the range reported in the literature.We found that the presence of magnetic fields influences the escaping neutral planetary material spreading the absorption Lyα line for large stellar magnetic fields.

scholarly journals Effect of magnetic fields on cryptochrome-dependent responses in Arabidopsis thaliana

2009 ◽  
Vol 6 (41) ◽  
pp. 1193-1205 ◽  
Author(s):  
Sue-Re Harris ◽  
Kevin B. Henbest ◽  
Kiminori Maeda ◽  
John R. Pannell ◽  
Christiane R. Timmel ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Arabidopsis Thaliana ◽  
Magnetic Fields ◽  
Low Frequency ◽  
Zero Field ◽  
Experimental Conditions ◽  
Replication Studies ◽  
Weak Magnetic Fields ◽  
Simultaneous Control ◽  
Independent Replication

The scientific literature describing the effects of weak magnetic fields on living systems contains a plethora of contradictory reports, few successful independent replication studies and a dearth of plausible biophysical interaction mechanisms. Most such investigations have been unsystematic, devoid of testable theoretical predictions and, ultimately, unconvincing. A recent study, of magnetic responses in the model plant Arabidopsis thaliana , however, stands out; it has a clear hypothesis—that seedling growth is magnetically sensitive as a result of photoinduced radical-pair reactions in cryptochrome photoreceptors—tested by measuring several cryptochrome-dependent responses, all of which proved to be enhanced in a magnetic field of intensity 500 μT. The potential importance of this study in the debate on putative effects of extremely low-frequency electromagnetic fields on human health prompted us to subject it to the ‘gold standard’ of independent replication. With experimental conditions chosen to match those of the original study, we have measured hypocotyl lengths and anthocyanin accumulation for Arabidopsis seedlings grown in a 500 μT magnetic field, with simultaneous control experiments at 50 μT. Additionally, we have determined hypocotyl lengths of plants grown in 50 μT, 1 mT and approximately 100 mT magnetic fields (with zero-field controls), measured gene ( CHS , HY5 and GST ) expression levels, investigated blue-light intensity effects and explored the influence of sucrose in the growth medium. In no case were consistent, statistically significant magnetic field responses detected.

Performance Evaluation of an MR-Compatible Rotating Anode X-Ray Tube

2013 ◽  
Author(s):  
Mihye Shin ◽  
Prasheel Lillaney ◽  
Waldo Hinshaw ◽  
Rebecca Fahrig
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Moments ◽  
X Ray ◽  
Close Proximity ◽  
Motor Design ◽  
Design Requirements ◽  
And Performance ◽  
The Magnetic Field ◽  
Lorentz Force Law

The key technical innovation needed for close proximity hybrid x-ray/MR (XMR) imaging systems is a new rotating anode x-ray tube motor that can operate in the presence of strong magnetic fields. In order for the new motor design to be optimized between conflicting design requirements, we implemented a numerical model for evaluating the dynamics of the motor. The model predicts the amount of produced torque, rotation speed, and time to accelerate based on the Lorentz force law; the motor is accelerated by the interaction between the magnetic moments of the motor wire loops and an external magnetic field. It also includes an empirical model of bearing friction and electromagnetic force from the magnetic field. Our proposed computational model is validated by experiments using several different magnitudes of external magnetic fields, which averagely shows an agreement within 0.5 % error during acceleration. We are using this model to improve the efficiency and performance of future iterations of the x-ray tube motor.

scholarly journals Analog Video Magnetograms in Real Time

1971 ◽  
Vol 43 ◽  
pp. 76-83 ◽  
Author(s):  
R. C. Smithson ◽  
R. B. Leighton
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Solar Magnetic Field ◽  
Solar Spectrum ◽  
Zeeman Splitting ◽  
The Other ◽  
Line Of Sight ◽  
Zero Field ◽  
The Sun ◽  
Solar Magnetic Fields

For many years solar magnetic fields have been measured by a variety of techniques, all of which exploit the Zeeman splitting of lines in the solar spectrum. One of these techniques (Leighton, 1959) involves a photographic subtraction of two monochromatic images to produce a picture of the Sun in which the line-of-sight component of the solar magnetic field appears as various shades of gray. In a magnetogram made by this method, zero field strength appears as neutral gray, while magnetic fields of one polarity or the other appear as lighter or darker areas, respectively. Figure 1 shows such a magnetogram.

HIGH-FIELD TRANSPORT PROPERTIES OF T'-Ln2-xCexCuO4 (Ln=Nd, Pr, La)

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3216-3219 ◽  
Author(s):  
T. SEKITANI ◽  
N. MIURA ◽  
M. NAITO
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Magnetic Fields ◽  
Transport Properties ◽  
Normal State ◽  
Low Temperatures ◽  
High Field ◽  
Magnetic Moments ◽  
Negative Magnetoresistance ◽  
High Magnetic Fields

We report low-temperature magnetotransport in the normal state of the electron-doped superconductors, Nd 2-x Ce x CuO 4, Pr 2-x Ce x CuO 4, and La 2-x Ce x CuO 4, by suppressing the superconductivity with high magnetic fields. The normal state ρ-T curve shows an up-turn at low temperatures, which has a log T dependence with saturation at lowest temperatures. The up-turn is gradually suppressed with increasing magnetic field, resulting in negative magnetoresistance. We discuss these findings on the basis of the Kondo scattering originating from the magnetic moments of Cu 2+ ions.

Rotational structure of triplet–singlet transitions in orthorhombic molecules in intermediate and high magnetic fields

1977 ◽  
Vol 55 (12) ◽  
pp. 1066-1073 ◽  
Author(s):  
C. di Lauro ◽  
E. Perri
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetic Fields ◽  
External Field ◽  
Triplet State ◽  
Rotational Structure ◽  
High Magnetic Fields ◽  
Zero Field ◽  
High Fields

The Zeeman band profiles are calculated for near-case (b) triplet–singlet transitions in asymmetric rotors, making allowance for the intensity perturbations induced by an external magnetic field. It is shown that new bands correlating with zero-field forbidden lines can be observed under the effect of sufficiently high fields. Band profiles and the patterns of the magnetic sublevels of the triplet state split by the external field are discussed in detail for the Paschen–Back limit.

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