VORTEX MAGNETISM IN THE HIGH-TEMPERATURES SUPERCONDUCTOR La2-xSrxCuO4

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3155-3155
Author(s):  
B. LAKE ◽  
T. E. MASON ◽  
G. AEPPLI ◽  
K. LEFMANN ◽  
N. B. CHRISTENSEN ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Normal State ◽  
Cuprate Superconductors ◽  
High Temperature Superconductivity ◽  
Field Measurements ◽  
Spin Fluctuations ◽  
Magnetic Interactions ◽  
Zero Field ◽  
Zero Resistance ◽  
Lower Temperature

There is strong evidence that magnetic interactions play a crucial role in the mechanism driving high-temperature superconductivity in cuprate superconductors. To investigate this further we have done a series of neutron scattering measurements on La 2-x Sr x CuO 4 (LSCO) in an applied magnetic field. Below Tc the field penetrates the superconductor via an array of normal state metallic inclusions or vortices. Phase coherent superconductivity characterized by zero resistance sets in at the lower field-dependent irreversibility temperature (Tirr). We have measured optimally doped LSCO (x = 0.16, Tc = 38.5 K ) and underdoped LSCO (x = 0.10, Tc = 29 K ); both have an enhanced antiferromagnetic response in a field. Measurements of the optimally doped system at H = 7.5 T show that sub-gap spin fluctuations first disappear with the loss of finite resistivity at Tirr, but then reappear at a lower temperature with increased lifetime and correlation length compared to the normal state. In the underdoped system elastic antiferromagnetism develops below Tc in zero field, and is significantly enhanced by application of a magnetic field. Phase coherent superconductivity is then established within the antiferromagnetic phase at Tirr; thus, the situation in underdoped LSCO is the reverse of that for the optimally doped LSCO where the zero-resistance state develops first before the onset of antiferromagnetism.

FIELD-INDUCED ANTIFERROMAGNETISM IN THE HIGH-TEMPERATURE SUPERCONDUCTOR La2-xSrxCuO4

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3197-3197
Author(s):  
B. LAKE ◽  
T. E. MASON ◽  
G. AEPPLI ◽  
K. LEFMANN ◽  
N. B. CHRISTENSEN ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Normal State ◽  
Cuprate Superconductors ◽  
High Temperature Superconductivity ◽  
Field Measurements ◽  
Spin Fluctuations ◽  
Magnetic Interactions ◽  
Zero Field ◽  
Zero Resistance

There is strong evidence that magnetic interactions play a crucial role in the mechanism driving high-temperature superconductivity in cuprate superconductors. To investigate this we have done a series of neutron scattering measurements on La 2-x Sr x CuO 4 (LSCO) in an applied magnetic field. Below Tc the field penetrates the superconductor via an array of normal state metallic inclusions or vortices. Phase coherent superconductivity characterized by zero resistance sets in at the lower field-dependent irreversibility temperature (Tirr). We have measured optimally doped LSCO (x = 0.16, Tc = 38.5 K ) and under-doped LSCO ( x = 0.10, Tc = 29 K ); both have an enhanced antiferromagnetic response in a field. Measurements of the optimally doped system at H = 7.5 T show that sub-gap spin fluctuations first disappear with the loss of finite resistivity at Tirr, but then reappear at a lower temperature with increased lifetime and correlation length compared to the normal state. In the under-doped system elastic antiferromagnetism develops below Tc in zero field, and is significantly enchanced by application of a magnetic field. Phase coherent superconductivity is then established within the antiferromagnetic phase at Tirr; thus, the situation in under-doped LSCO is the reverse of that for the optimally doped LSCO where the zero-resistance state develops first before the onset of antiferromagnetism.

STABLE hc/e VORTICES IN SUPERCONDUCTORS WITH SPIN-CHARGE SEPARATION

1992 ◽  
Vol 06 (05n06) ◽  
pp. 509-526
Author(s):  
Subir Sachdev
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Normal State ◽  
Phenomenological Model ◽  
Charge Separation ◽  
Cuprate Superconductors ◽  
Superconducting Phase ◽  
Low Energy ◽  
Large N ◽  
Normal State Properties

A phenomenological model, F, of the superconducting phase of systems with spin-charge separation and antiferromagnetically induced pairing is studied. Above Hc1, magnetic flux can always pierce the superconductor in vortices with flux hc/2e, but regimes are found in which vortices with flux hc/e are preferred. Little-Park and other experiments, which examine periodicities with a varying magnetic field, always observe a period of hc/2e. The low energy properties of a symplectic large-N expansion of a model of the cuprate superconductors are argued to be well described by F. This analysis and some normal state properties of the cuprates suggest that hc/e vortices should be stable at the lowest dopings away from the insulating state at which superconductivity first occurs.

MAGNETIC NANOCHAINS: A REVIEW

NANO ◽  
2011 ◽  
Vol 06 (01) ◽  
pp. 1-17 ◽  
Author(s):  
HUI WANG ◽  
YIFEI YU ◽  
YUBIN SUN ◽  
QIANWANG CHEN
Keyword(s):  
Magnetic Field ◽  
Self Assembly ◽  
Magnetic Interactions ◽  
Synthesis Methods ◽  
Zero Field ◽  
Magnetic Recording Media ◽  
1D Chain ◽  
Potential Applications ◽  
Micromechanical Sensors ◽  
Nanoparticle Chains

One-dimensional (1D) chain-like structures are of special significance because of their interparticle magnetic interactions and potential applications in various fields, such as micromechanical sensors. This paper attempts to review the field of research into magnetic chains including monatomic chains and nanoparticle chains. The synthesis methods used mostly belong to one of the following categories: magnetosome chains in magnetotactic bacteria, zero-field self-assembly, magnetic field induced (MFI) assembly, template-directed synthesis, and gas phase synthesis. The potential applications of nanoparticle chains, mainly in the field of magnetic recording media, sensor, biomedicine and magnetic-field tunable photonic crystal are discussed.

Melt-textured YBaCuO with High Trapped Fields up to 1.3 T at 77 K

2000 ◽  
Vol 15 (6) ◽  
pp. 1231-1234 ◽  
Author(s):  
H. Walter ◽  
M. P. Delamare ◽  
B. Bringmann ◽  
A. Leenders ◽  
H. C. Freyhardt
Keyword(s):  
Magnetic Field ◽  
Growth Process ◽  
Field Measurements ◽  
Transport Critical Current Density ◽  
Zero Field ◽  
Standard Samples ◽  
Trapped Field ◽  
Trapped Magnetic Field ◽  
Suitable Temperature ◽  
Scanning Electron

CeO2-doped YBaCuO monoliths synthesized with a top-seeded melt growth process in a conventional box furnace exhibited values of trapped magnetic field of up to 1.33 T at 77 K. To our knowledge, this is the highest value of trapped field reported for a melt-textured YBaCuO monolith. A suitable temperature profile and the use of high-density Y2BaCuO5 substrates led to reproducible single-domain crack-free samples investigated by optical and scanning electron microscopy and trapped field measurements. The zero-field-cooled levitation forces at 77 K of standard samples amounted to 70–83 N. A transport critical current density of up to 1.3 × 105 A/cm2 in self field at 77 K was obtained.

Magnetic Field Sensing with Atomic Scale Defects in SiC Devices

2016 ◽  
Vol 858 ◽  
pp. 265-268 ◽  
Author(s):  
Corey J. Cochrane ◽  
Jordana Blacksberg ◽  
Patrick M. Lenahan ◽  
Mark A. Anders
Keyword(s):  
Magnetic Field ◽  
Semiconductor Industry ◽  
High Sensitivity ◽  
Field Measurements ◽  
Wide Bandgap ◽  
Atomic Scale ◽  
Zero Magnetic Field ◽  
Zero Field ◽  
Field Sensing ◽  
Magnetic Field Sensing

Silicon carbide (SiC) is well known by the semiconductor industry to have significant potential for electronics used in high temperature environments due to its wide bandgap. It is not so well-known, however, that SiC also has great potential in the area of magnetic field sensing. Using the recently demonstrated zero-field spin dependent recombination (SDR) phenomenon that naturally arises in SiC based devices, near-zero magnetic field measurements can be made with moderately high sensitivity.

Magnetic Anomaly in the YBa2Cu3O7 System at Low External Magnetic Fields

1992 ◽  
Vol 275 ◽  
Author(s):  
Bokhimi
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Anomaly ◽  
Normal State ◽  
Vortex Lattice ◽  
Sample Temperature ◽  
Zero Field ◽  
Magnetization Curves ◽  
Diamagnetic Signal

ABSTRACTMagnetization curves for low external magnetic fields of field-cooled superconducting YBa2Cu3O7 samples show an increase in the diamagnetic signal when the sample temperature is near the transition to the normal state. The Increase of the diamagnetic signal depends on the external magnetic field (H ≤ 13.5 Oe). The effect is observed when the samples are field-cooled, but not when they are zero-field-cooled, that means that it is related with the behavior of the vortex lattice.

scholarly journals Large magnetodielectric coupling in the vicinity of metamagnetic transition in 6H−perovskite Ba3GdRu2O9

2022 ◽  
Author(s):  
Sonu Chhillar ◽  
Kaustav Mukherjee ◽  
C. S. Yadav
Keyword(s):  
Magnetic Field ◽  
Heat Capacity ◽  
Magnetic Behavior ◽  
Magnetic Interactions ◽  
Metamagnetic Transition ◽  
Lower Temperature Side ◽  
Lower Temperature ◽  
Transition Complex ◽  
The Magnetic Field ◽  
Temperature Side

Abstract The 6H-perovskites Ba3RRu2O9 (R = rare earth element) demonstrate the magnetodielectric (MD) coupling as a manifestation of 4d - 4f magnetic interactions. Here, we have reported a detailed study of the structural, magnetic, heat capacity, and MD properties of the 6H-perovskite Ba3GdRu2O9. The signature of long-range antiferromagnetic (AFM) ordering at ~14.8 K (TN) is evident from the magnetization and heat capacity studies. The TN shifts towards the lower temperature side, apart from splitting in two with the application of the magnetic field. Field-dependent magnetization at 2 K shows three metamagnetic transitions with the opening of small hysteresis in different regions. A new transition at T1 emerges after the onset of the first metamagnetic transition. Complex magnetic behavior is observed in different magnetic field regions whereas these field regions themselves vary with the temperature. Dielectric response recorded at zero and 80 kOe field exhibits the development of MD coupling well above TN. The MD coupling (~ 4.5 % at 10 K) is enhanced by 25 % as compared to the Dy counterpart. Effect of complex magnetic behavior is also conveyed in the MD results where the maximum value of MD coupling is observed in the vicinity of 10 K (onset of T1) and near the second metamagnetic transition. Our investigation suggests that both Gd and Ru moments align simultaneously at TN. Short-range magnetic correlations are possibly responsible for MD coupling above TN.

scholarly journals MAGNETIC-FIELD-INDUCED SUPERCONDUCTIVITY IN LAYERED ORGANIC MOLECULAR CRYSTALS WITH LOCALIZED MAGNETIC MOMENTS

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3071-3071
Author(s):  
O. CEPAS ◽  
R. H. MCKENZIE ◽  
J. MERINO
Keyword(s):  
Magnetic Field ◽  
Superconducting State ◽  
Magnetic Moments ◽  
Spin Fluctuations ◽  
Zero Field ◽  
Field Range ◽  
Organic Molecular Crystals ◽  
Magnetic Ions ◽  
The Magnetic Field

The synthetic organic compound λ (BETS) 2 FeCl 4 undergoes successive transitions from an antiferromagnetic insulator to a metal and then to a superconductor as a magnetic field is increased. We use a Hubbard-Kondo model to clarify the role of the Fe 3+ magnetic ions in these phase transition. In the high-field regime, the magnetic field acting on the electron spins is compensated by the exchange field He due to the magnetic ions. This suggests that the field-induced superconducting state is the same as the zero-field superconducting state which occurs under pressure or when the Fe 3+ ions are replaced by non-magnetic Ga 3+ ions. We show how Hc can be extracted from the observed splitting of the Shybnikov-de Haas frequencies. Furthermore, we use this method of extracting He to predict the field range for field-induced superconductivity in other materials. We also show that at high fields the spin fluctuations of the localized spins are not important.

scholarly journals Magnetic field reveals vanishing Hall response in the normal state of stripe-ordered cuprates

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhenzhong Shi ◽  
P. G. Baity ◽  
J. Terzic ◽  
Bal K. Pokharel ◽  
T. Sasagawa ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Hall Coefficient ◽  
Normal State ◽  
High Field ◽  
Fundamental Property ◽  
Zero Field ◽  
Superconducting Transition ◽  
Underdoped Cuprates ◽  
Competing Orders

AbstractThe origin of the weak insulating behavior of the resistivity, i.e. $${\rho }_{xx}\propto {\mathrm{ln}}\,(1/T)$$ ρ x x ∝ ln ( 1 / T ) , revealed when magnetic fields (H) suppress superconductivity in underdoped cuprates has been a longtime mystery. Surprisingly, the high-field behavior of the resistivity observed recently in charge- and spin-stripe-ordered La-214 cuprates suggests a metallic, as opposed to insulating, high-field normal state. Here we report the vanishing of the Hall coefficient in this field-revealed normal state for all $$T\ <\ (2-6){T}_{{\rm{c}}}^{0}$$ T < ( 2 − 6 ) T c 0 , where $${T}_{{\rm{c}}}^{0}$$ T c 0 is the zero-field superconducting transition temperature. Our measurements demonstrate that this is a robust fundamental property of the normal state of cuprates with intertwined orders, exhibited in the previously unexplored regime of T and H. The behavior of the high-field Hall coefficient is fundamentally different from that in other cuprates such as YBa2Cu3O6+x and YBa2Cu4O8, and may imply an approximate particle-hole symmetry that is unique to stripe-ordered cuprates. Our results highlight the important role of the competing orders in determining the normal state of cuprates.

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