scholarly journals Tuning Nanoscale Friction by Applying Weak Magnetic Fields to Reorient Adsorbed Oxygen Molecules

2018 ◽  
Vol 4 (1) ◽  
pp. 1 ◽  
Author(s):  
Z. Fredricks ◽  
K. Stevens ◽  
S. Kenny ◽  
B. Acharya ◽  
J. Krim
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Weak Magnetic Field ◽  
Quartz Crystal ◽  
Sliding Friction ◽  
Model Systems ◽  
Theoretical Studies ◽  
Weak Magnetic Fields ◽  
Gold Substrates

Sliding friction levels of thin (1–2 monolayers) and thick (~10 monolayers) oxygen films adsorbed on nickel and gold at 47.5 K have been measured by means of a quartz crystal microbalance (QCM) technique. Friction levels for the thin (thick) films on nickel in the presence of a weak magnetic field were observed to be approximately 30% (50%) lower than those recorded in the absence of the external field. Friction levels for thin films on gold were meanwhile observed to be substantially increased in the presence of the field. Magnetically-induced structural reorientation (magnetostriction) and/or realignment of adlayer spins, which respectively reduce structural and magnetic interfacial corrugation and commensurability, appear likely mechanisms underlying the observed field-induced reductions in friction for the nickel samples. Eddy current formation in the gold substrates may account for the increased friction levels in this system. The work demonstrates the role of magnetic effects in model systems that are highly amenable to theoretical studies and modeling.

The Role of Oxygen in the Priming of Neutrophils on Exposure to a Weak Magnetic Field

BIOPHYSICS ◽  
2018 ◽  
Vol 63 (2) ◽  
pp. 193-196 ◽  
Author(s):  
V. V. Novikov ◽  
E. V. Yablokova ◽  
E. E. Fesenko
Keyword(s):  
Magnetic Field ◽  
Weak Magnetic Field

Nanostructured Organic Thin Films: Electronic Energetics and Devices

2001 ◽  
Vol 15 (28n30) ◽  
pp. 3722-3726 ◽  
Author(s):  
C. TALIANI ◽  
F. BISCARINI ◽  
E. LUNEDEI ◽  
P. Mei ◽  
M. Muccini ◽  
...  
Keyword(s):  
Thin Films ◽  
Energy Transfer ◽  
Vibrational Spectroscopy ◽  
Crystal Packing ◽  
Organic Thin Films ◽  
Model Systems ◽  
Conjugation Length ◽  
Time Dynamics ◽  
Transfer Processes

We report on the optoelectronic properties of vacuum sublimed organic thin films of the oligothienyls ( Tn ) model systems. The Davydov splitting (DS) of the lowest exciton is about 0.3 eV and decreases with the conjugation length when going from T 4 to T 6. The lowest DS component is partially forbidden due to the crystal packing and the spectral activity occurs via Herzberg-Teller (HT) vibronic coupling. We show the real time dynamics of the HT coupling by coherent vibrational spectroscopy and the role of aggregates in the energy transfer processes within the films.

The role of applied magnetic field in Co-doped ZnS thin films fabricated by pulsed laser deposition

2021 ◽  
Vol 114 ◽  
pp. 110877
Author(s):  
Dongwen Gao ◽  
Li Wang ◽  
Xueqiong Su ◽  
Jin Wang ◽  
Ruixiang Chen
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Applied Magnetic Field ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Co Doped

scholarly journals Magnetic fields in astrophysical objects

2008 ◽  
Vol 366 (1884) ◽  
pp. 4453-4464 ◽  
Author(s):  
L.J Silvers
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Large Scale ◽  
Accretion Discs ◽  
Weak Magnetic Fields ◽  
Large Scale Magnetic Field ◽  
Astrophysical Objects ◽  
Recent Developments ◽  
The Magnetic Field

Magnetic fields are known to reside in many astrophysical objects and are now believed to be crucially important for the creation of phenomena on a wide variety of scales. However, the role of the magnetic field in the bodies that we observe has not always been clear. In certain situations, the importance of a magnetic field has been overlooked on the grounds that the large-scale magnetic field was believed to be too weak to play an important role in the dynamics. In this article I discuss some of the recent developments concerning magnetic fields in stars, planets and accretion discs. I choose to emphasize some of the situations where it has been suggested that weak magnetic fields may play a more significant role than previously thought. At the end of the article, I list some of the questions to be answered in the future.

The Velocity of Current Filaments in Weak Magnetic Fields

1994 ◽  
Vol 49 (9) ◽  
pp. 847-850 ◽  
Author(s):  
Thomas Christen
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Weak Magnetic Field ◽  
Simple Type ◽  
Goldstone Mode ◽  
Current Filament ◽  
Weak Magnetic Fields ◽  
Hall Angle ◽  
Collective Coordinate ◽  
Current Filaments

Abstract In the presence of a perpendicular weak magnetic field, current filaments in semiconductors can obtain a transverse drift. In the framework of a collective-coordinate ansatz, an expression for the velocity of the filament is derived for a simple type of extrinsic semiconductors. It turns out that the motion is caused by the coupling of the non-uniform Hall angle to the translational Goldstone mode of the current filament.

scholarly journals Pulsation of Rotating and Magnetic Stars

1993 ◽  
Vol 137 ◽  
pp. 497-511 ◽  
Author(s):  
Sergei V. Vorontsov
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Spherical Symmetry ◽  
Slow Rotation ◽  
Theoretical Studies ◽  
Pulsating Stars ◽  
Magnetic Effects ◽  
Weak Magnetic Fields ◽  
Magnetic Stars ◽  
Oscillation Frequencies

AbstractRotation and a magnetic field break the spherical symmetry of a star viewed as a pulsating system, lifting the degeneracy of oscillation frequencies, and leading to (sometimes prominent) observational consequences. Theoretical studies of rotational and magnetic effects in pulsating stars are reviewed, starting with simple configurations with slow rotation and weak magnetic fields.

scholarly journals Blazar Optical Polarimetry: Current Progress in Observations and Theories

Galaxies ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 85 ◽  
Author(s):  
Haocheng Zhang
Keyword(s):  
Magnetic Field ◽  
High Energy ◽  
Theoretical Studies ◽  
First Principle ◽  
Standard Tool ◽  
Multi Wavelength ◽  
Radiation Processes ◽  
The Magnetic Field ◽  
Shed Light

Polarimetry has been a standard tool to probe the active galactic nucleus (AGN) jet magnetic field. In recent years, several optical polarization monitoring programs have been carried out, bringing in many exciting new results and insights into jet dynamics and emission. This article discusses current progress in blazar optical polarimetry. The main focus is the variability of polarization signatures, which has spurred a lot of theoretical studies. These novel developments have provided unique constraints on the blazar flares and emphasized the role of the magnetic field in jet evolution. Optical polarimetry will continue to act as an essential component in the multi-messenger study of AGN jets, in particular with the upcoming high-energy polarimetry. Comparing to first-principle numerical simulations, future multi-wavelength polarimetry can shed light on jet dynamics, particle acceleration, and radiation processes.

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