Dependence of the specific heat of a La1.85Sr0.15CuO4 superconducting single crystal on the magnetic field direction in the a-b plane

JETP Letters ◽  
1997 ◽  
Vol 66 (11) ◽  
pp. 715-719 ◽  
Author(s):  
M. N. Khlopkin ◽  
G. Kh. Panova ◽  
N. A. Chernoplekov ◽  
A. A. Shikov
Keyword(s):  
Magnetic Field ◽  
Single Crystal ◽  
Specific Heat ◽  
Field Direction ◽  
Magnetic Field Direction ◽  
The Magnetic Field

A 3 T superconducting magnet for long-run magnetic Compton-scattering experiments

1998 ◽  
Vol 5 (3) ◽  
pp. 937-939 ◽  
Author(s):  
Nobuhiko Sakai ◽  
Hiroshi Ohkubo ◽  
Yasushi Nakamura
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Compton Scattering ◽  
Superconducting Magnet ◽  
Field Direction ◽  
Compton Profile ◽  
Magnetic Field Direction ◽  
Long Run ◽  
Radiation Shields ◽  
The Magnetic Field

A 3 T superconducting magnet has been designed and constructed for magnetic Compton-profile (MCP) measurements with the new capabilities that the magnetic field direction can be altered quickly (within 5 s) and liquid-He refill is not required for more than one week. For the latter capability, two refrigerators have been directly attached to the cryostat to maintain the low temperature of the radiation shields and for the recondensation of liquid He. The system has been satisfactorily operated for over one week.

scholarly journals Mid-infrared Observations of Magnetic Fields in the Disks of Bi-Polar Outflow Sources

1997 ◽  
Vol 163 ◽  
pp. 799-800
Author(s):  
Craig H. Smith ◽  
Christopher M. Wright ◽  
David K. Aitken ◽  
Patrick F. Roche
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Field Configuration ◽  
Field Direction ◽  
Magnetic Field Direction ◽  
Poloidal Field ◽  
Mid Infrared ◽  
Infrared Observations ◽  
Polarization Mechanism ◽  
The Magnetic Field

AbstractWe present the results from mid-infrared spectro-polarimetric observations of a number of bi-polar outflow sources. The specto-polarimetric data provides information on the polarization mechanism and the magnetic field direction. The field direction in the disks of the observed sources is most often normal to the ambient field direction and lies in the plane of the disk, indicating a toroidal rather than poloidal field configuration.

scholarly journals Equation of State of a Magnetized Dense Neutron System

Universe ◽  
2019 ◽  
Vol 5 (5) ◽  
pp. 104 ◽  
Author(s):  
Efrain J. Ferrer ◽  
Aric Hackebill
Keyword(s):  
Magnetic Field ◽  
Equation Of State ◽  
Chemical Potential ◽  
Compact Objects ◽  
Field Direction ◽  
Neutron Density ◽  
Magnetic Field Direction ◽  
System Equation ◽  
The One ◽  
The Magnetic Field

We discuss how a magnetic field can affect the equation of state of a many-particle neutron system. We show that, due to the anisotropy in the pressures, the pressure transverse to the magnetic field direction increases with the magnetic field, while the one along the field direction decreases. We also show that in this medium there exists a significant negative field-dependent contribution associated with the vacuum pressure. This negative pressure demands a neutron density sufficiently high (corresponding to a baryonic chemical potential of μ = 2.25 GeV) to produce the necessary positive matter pressure that can compensate for the gravitational pull. The decrease of the parallel pressure with the field limits the maximum magnetic field to a value of the order of 10 18 G, where the pressure decays to zero. We show that the combination of all these effects produces an insignificant variation of the system equation of state. We also found that this neutron system exhibits paramagnetic behavior expressed by the Curie’s law in the high-temperature regime. The reported results may be of interest for the astrophysics of compact objects such as magnetars, which are endowed with substantial magnetic fields.

scholarly journals Magnetic clouds' structure in the magnetosheath as observed by Cluster and Geotail: four case studies

2014 ◽  
Vol 32 (10) ◽  
pp. 1247-1261 ◽  
Author(s):  
L. Turc ◽  
D. Fontaine ◽  
P. Savoini ◽  
E. K. J. Kilpua
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Magnetic Fields ◽  
Bow Shock ◽  
Field Direction ◽  
Magnetic Clouds ◽  
Magnetic Field Direction ◽  
Field Orientation ◽  
The Impact ◽  
The Magnetic Field

Abstract. Magnetic clouds (MCs) are large-scale magnetic flux ropes ejected from the Sun into the interplanetary space. They play a central role in solar–terrestrial relations as they can efficiently drive magnetic activity in the near-Earth environment. Their impact on the Earth's magnetosphere is often attributed to the presence of southward magnetic fields inside the MC, as observed in the upstream solar wind. However, when they arrive in the vicinity of the Earth, MCs first encounter the bow shock, which is expected to modify their properties, including their magnetic field strength and direction. If these changes are significant, they can in turn affect the interaction of the MC with the magnetosphere. In this paper, we use data from the Cluster and Geotail spacecraft inside the magnetosheath and from the Advanced Composition Explorer (ACE) upstream of the Earth's environment to investigate the impact of the bow shock's crossing on the magnetic structure of MCs. Through four example MCs, we show that the evolution of the MC's structure from the solar wind to the magnetosheath differs largely from one event to another. The smooth rotation of the MC can either be preserved inside the magnetosheath, be modified, i.e. the magnetic field still rotates slowly but at different angles, or even disappear. The alteration of the magnetic field orientation across the bow shock can vary with time during the MC's passage and with the location inside the magnetosheath. We examine the conditions encountered at the bow shock from direct observations, when Cluster or Geotail cross it, or indirectly by applying a magnetosheath model. We obtain a good agreement between the observed and modelled magnetic field direction and shock configuration, which varies from quasi-perpendicular to quasi-parallel in our study. We find that the variations in the angle between the magnetic fields in the solar wind and in the magnetosheath are anti-correlated with the variations in the shock obliquity. When the shock is in a quasi-parallel regime, the magnetic field direction varies significantly from the solar wind to the magnetosheath. In such cases, the magnetic field reaching the magnetopause cannot be approximated by the upstream magnetic field. Therefore, it is important to take into account the conditions at the bow shock when estimating the impact of an MC with the Earth's environment because these conditions are crucial in determining the magnetosheath magnetic field, which then interacts with the magnetosphere.

Effect of temperature on magnetic susceptibility and thermodynamic properties of an asymmetric quantum dot in tilted magnetic field

2015 ◽  
Vol 29 (23) ◽  
pp. 1550127 ◽  
Author(s):  
R. Khordad
Keyword(s):  
Magnetic Field ◽  
Magnetic Susceptibility ◽  
Quantum Dot ◽  
Specific Heat ◽  
Energy Levels ◽  
Effect Of Temperature ◽  
Magnetic Field Direction ◽  
Asymmetric Quantum ◽  
Gaas Quantum Dot ◽  
The Magnetic Field

In this paper, the specific heat, entropy and magnetic susceptibility of an asymmetric GaAs quantum dot (QD) are studied under the influence of temperature and a tilted external magnetic field. We first calculate the analytical wave functions and energy levels using a transformation to simplify the Hamiltonian of the system. Then, we obtain the analytical expressions for specific heat, entropy and magnetic susceptibility as the function of temperature, magnetic field and its direction for various anisotropy of the system. According to the results obtained from the present work, we find that (i) the specific heat and entropy are decreased when the magnetic field increases. (ii) When anisotropy is increased, the specific heat and entropy decrease. (iii) At large magnetic fields, the anisotropy has not important effect on specific heat and entropy. In briefly, the magnetic field, magnetic field direction and anisotropy play important roles in the specific heat, entropy and magnetic susceptibility of an asymmetric QD.

Crystallographic orientation of primary and eutectic phases in a hypoeutectic Mn–Sb alloy induced by solidification in high magnetic fields

2019 ◽  
Vol 52 (5) ◽  
pp. 945-950 ◽  
Author(s):  
Shulin Dong ◽  
Tie Liu ◽  
Meng Dong ◽  
Shuang Wang ◽  
Wen Wang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Crystallographic Orientation ◽  
Field Direction ◽  
High Magnetic Fields ◽  
Magnetic Field Direction ◽  
Eutectic Alloys ◽  
Random Orientation ◽  
Binary Eutectic ◽  
The Magnetic Field

This paper investigates how applying high magnetic fields influences the crystallographic orientations of the primary and eutectic phases, and their relationship, in a binary eutectic alloy. At 0 T, the primary MnSb phase in hypoeutectic Mn–Sb showed a random orientation, but at 3, 6, 9 and 11.5 T, its c axis was perpendicular to the magnetic field direction. In all cases, the eutectic MnSb phases showed the same orientations as their neighboring primary MnSb phase, on which they nucleated and grew. With high magnetic fields, the c axes of the eutectic and primary MnSb phases were oriented perpendicular to the magnetic field direction. The results show that applying a high magnetic field during solidification is a way of controlling the crystallographic orientation of both the primary and the eutectic phases in eutectic alloys.

Effects of High Magnetic Field Heat Treatment on the Microstructure of Fe-0.76%C Alloy

2011 ◽  
Vol 704-705 ◽  
pp. 863-869 ◽  
Author(s):  
Ming Long Gong ◽  
Xiang Zhao ◽  
Chang Shu He ◽  
J.Y. Song ◽  
Liang Zuo
Keyword(s):  
Magnetic Field ◽  
High Magnetic Field ◽  
Lamellar Spacing ◽  
Field Direction ◽  
Magnetic Field Direction ◽  
High Carbon Content ◽  
Proeutectoid Ferrite ◽  
Alloy Microstructure ◽  
And Shifts ◽  
The Magnetic Field

The present studies are to investigate the microstructure features during transformation from austenite to ferrite without and with magnetic field on Fe-0.76%C alloy. It is found that the area fraction and numbers of proeutectoid ferrite grain as well as the lamellar spacing of pearlite in Fe-0.76%C alloy increased considerably with the increase of magnetic field intensity. The reason is that, the magnetic field increases the driving force of proeutectoid ferrite nuclei and shifts the eutectoid point to the side of high carbon content and high temperature, which increases the starting-temperature of the transformation from austenite to ferrite. The proeutectoid ferrite grains are elongated along the magnetic field direction, which can be explained as follows: the proeutectoid ferrite becomes the magnetic dipolar under high magnetic field, and then the polarized austenite atoms are much easier to diffuse into ferrite grains along the magnetic field direction. Key words: high magnetic field; Fe-0.76%C alloy; microstructure

Pressure Dependence of the de Haas – van Alphen Effect in Ytterbium

1974 ◽  
Vol 52 (17) ◽  
pp. 1622-1627 ◽  
Author(s):  
A. J. Slavin ◽  
W. R. Datars
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Phase Transformation ◽  
Pressure Dependence ◽  
Experimental Error ◽  
Solid Helium ◽  
Field Direction ◽  
Magnetic Field Direction ◽  
Pressure Medium ◽  
The Magnetic Field

The de Haas–van Alphen effect and the h.c.p.–f.c.c. phase transformation of ytterbium were studied with the magnetic field along the [0001] direction in the h.c.p. phase, using pressures up to 4 kbar. Solid helium was used as the pressure medium. The pressure dependence of the three dHvA frequencies in the h.c.p. phase for the [0001] magnetic field direction was linear within experimental error with dF/dP = −1.2 ± 0.2 T/kbar for F(P = 0) of 35.4 T, dF/dP = 0.30 ± 0.03 T/kbar for F(P = 0) of 142.5 T, and dF/dP = −0.78 ± 0.10 T/kbar for F(P = 0) of 156.4 T. The dHvA amplitude in the h.c.p. phase was independent of pressure up to the phase transition and no dHvA effect was observed in the f.c.c. phase. The pressure of the phase transformation at 1.2 K was determined to be 2.15 ± 0.05 kbar.

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