Notizen: Reactivation of Mechanical Aftereffect of Iron Single Crystals by Discontinuous Change of External Magnetic Field

1972 ◽  
Vol 27 (2) ◽  
pp. 371-372 ◽  
Author(s):  
H. Markert

AbstractFirst experiments on iron single crystals are outlined demonstrating that the mechanical aftereffect can be reactivated remarkably by discontinuous changes in superimposed magnetic fields. As magnetostrictive effects not only are very much smaller but can also be separated experimentally, it appears to be necessary to interpret the observed phenomena by interactions between domain walls and dislocations having mutual orientations suitable to enable reactivation of disclocation glide caused by the repulsive interaction forces of the domain walls.

1974 ◽  
Vol 29 (3) ◽  
pp. 457-461
Author(s):  
H. Markert

A zero approximation has been given of the normalized vaulting amplitudes of 180°-domain walls which are assumed to be vaulted between repulsive interaction lines if equilibrium has taken place between an external magnetic field and the counteracting forces resulting from the stray fields of the vaulting-induced free magnetic surface poles. Calculations have been carried out for two cases: cylindrical vaulting between linear barrier lines and pillow-shaped vaulting between isolated interaction points building up a tridimensional lattice of hindering points


RSC Advances ◽  
2021 ◽  
Vol 11 (25) ◽  
pp. 15422-15427
Author(s):  
Petr A. Chernavsky ◽  
Nellie V. Kim ◽  
Victor A. Andrianov ◽  
Yurii D. Perfiliev ◽  
Alla A. Novakova ◽  
...  

The kinetics of hydrogen reduction of magnetite was investigated in different magnetic fields.


RSC Advances ◽  
2021 ◽  
Vol 11 (28) ◽  
pp. 17051-17057
Author(s):  
Anna Eichler-Volf ◽  
Yara Alsaadawi ◽  
Fernando Vazquez Luna ◽  
Qaiser Ali Khan ◽  
Simon Stierle ◽  
...  

PS/CoPd Janus particles respond very sensitively to application of low external magnetic fields. Owing to the magnetic properties, the PS/CoPd particles may be used, for example, to sense the presence of weak magnetic fields as micro-magnetometers.


2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Yogesh Kumar ◽  
Rabia Sultana ◽  
Prince Sharma ◽  
V. P. S. Awana

AbstractWe report the magneto-conductivity analysis of Bi2Se3 single crystal at different temperatures in a magnetic field range of ± 14 T. The single crystals are grown by the self-flux method and characterized through X-ray diffraction, Scanning Electron Microscopy, and Raman Spectroscopy. The single crystals show magnetoresistance (MR%) of around 380% at a magnetic field of 14 T and a temperature of 5 K. The Hikami–Larkin–Nagaoka (HLN) equation has been used to fit the magneto-conductivity (MC) data. However, the HLN fitted curve deviates at higher magnetic fields above 1 T, suggesting that the role of surface-driven conductivity suppresses with an increasing magnetic field. This article proposes a speculative model comprising of surface-driven HLN and added quantum diffusive and bulk carriers-driven classical terms. The model successfully explains the MC of the Bi2Se3 single crystal at various temperatures (5–200 K) and applied magnetic fields (up to 14 T).


2015 ◽  
Vol 15 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Matthias Ratajczak ◽  
Thomas Wondrak ◽  
Klaus Timmel ◽  
Frank Stefani ◽  
Sven Eckert

AbstractIn continuous casting DC magnetic fields perpendicular to the wide faces of the mold are used to control the flow in the mold. Especially in this case, even a rough knowledge of the flow structure in the mold would be highly desirable. The contactless inductive flow tomography (CIFT) allows to reconstruct the dominating two-dimensional flow structure in a slab casting mold by applying one external magnetic field and by measuring the flow-induced magnetic fields outside the mold. For a physical model of a mold with a cross section of 140 mm×35 mm we present preliminary measurements of the flow field in the mold in the presence of a magnetic brake. In addition, we show first reconstructions of the flow field in a mold with the cross section of 400 mm×100 mm demonstrating the upward scalability of CIFT.


1980 ◽  
Vol 35 (11) ◽  
pp. 1271-1272 ◽  
Author(s):  
W. Henke ◽  
H. L. Selzle ◽  
T. R. Hays ◽  
E. W. Schlag

Abstract The effect of an external magnetic field on the decay of an excited single rotational state of the 1Au electronic state of biacetyl is observed in a hypersonic jet experiment after narrow bandwidth laser excitation. The lifetime of the ex-cited state decreases already at low magnetic fields and the molecular quantum beat vanishes.


Author(s):  
A. SARGSYAN ◽  
G. HAKHUMYAN ◽  
R. MIRZOYAN ◽  
A. PAPOYAN ◽  
D. SARKISYAN ◽  
...  

Recently it was shown that "λ-Zeeman Technique" (λ-ZT) is a convenient tool to study individual transitions between the Zeeman sublevels of hyperfine levels in an external magnetic field. λ-ZT is based on resonant transmission spectrum of nanometric thin cell (NTC) of thickness L = λ, where λ is the resonant wavelength 794 nm for Rb D1 line. Narrow velocity selective optical pumping (VSOP) resonances in the transmission spectrum of the NTC are split into several components in a magnetic field. Examination of VSOP resonances allows one to identify and investigate an atomic transition in the range of magnetic fields 10 - 5000 G. Here we present a new method for selective addressing of VSOP resonance amplification (more than 10 times).


Author(s):  
G. A. Govor ◽  
A. O. Larin ◽  
V. I. Mitsiuk ◽  
G. S. Rimskiy ◽  
T. M. Tkachenkа

The Stockbargard – Bridgman method yielded single crystals Mn0.99Fe0.01As. The effect of an external magnetic field with an intensity of up to 10 T on phase transitions in the single crystal Mn0.99Fe0.01As is studied. It is established that the magnetostructural phase transition in Mn0.99Fe0.01As is accompanied by a change in the entropy ΔSm, which is due to the transformation of the crystal structure. At temperatures above the temperature of the magnetostructural transition Tu = 290 K, the existence of an unstable magnetic structure is obtained. The magnetocaloric characteristics of the material under study are determined by an indirect calculation method based on the Maxwell thermodynamic relations and the Clapeyron – Clausius equation.


2011 ◽  
Vol 2011 ◽  
pp. 1-3
Author(s):  
S. G. Chigarev ◽  
E. M. Epshtein ◽  
I. V. Malikov ◽  
G. M. Mikhailov ◽  
P. E. Zilberman

A magnetic tunnel junction Fe3O4/MgO/Fe with (001) layer orientation is considered. The junction magnetic energy is analyzed as a function of the angle between the layer magnetization vectors under various magnetic fields. The tunnel magnetoresistance is calculated as a function of the external magnetic field. In contrast with junctions with unidirectional anisotropy, a substantially lower magnetic field is required for the junction switching.


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