scholarly journals Superconducting Order Parameter Nucleation and Critical Currents in the Presence of Weak Stray Fields in Superconductor/Insulator/Ferromagnet Hybrids

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 507
Author(s):  
Vasiliy N. Kushnir ◽  
Serghej L. Prischepa ◽  
Michela Trezza ◽  
Carla Cirillo ◽  
Carmine Attanasio
Keyword(s):  
Phenomenological Theory ◽  
Critical Currents ◽  
Superconducting Phase ◽  
Stray Field ◽  
Superconducting Properties ◽  
Ginzburg Landau ◽  
Ferromagnetic Layers ◽  
Linearized System ◽  
Critical Current Density Jc ◽  
Usadel Equations

The stray fields produced by ferromagnetic layers in Superconductor/Insulator/Ferromagnet (S/I/F) heterostructures may strongly influence their superconducting properties. Suitable magnetic configurations can be exploited to manipulate the main parameters of the hybrids. Here, the nucleation of the superconducting phase in an external magnetic field that periodically oscillates along the film width is studied on the base of the numerical solution of the linearized system of Usadel equations. In addition, the effect of the magnetic configuration of the F-layer on the temperature dependence of the critical current density, Jc(T), is investigated in the framework of the Ginzburg–Landau phenomenological theory on the base of the oscillating model of a stray field. By following this approach, the Jc(T) dependence of a Nb/SiO2/PdNi trilayer is reproduced for different magnetic configurations of the PdNi layer.

The role of the stray field on superconducting properties of hybrid ferromagnetic/superconducting heterostructures

2020 ◽  
Vol 128 (4) ◽  
pp. 043902
Author(s):  
A. Paschoa ◽  
J. L. Gonzalez ◽  
V. P. Nascimento ◽  
E. C. Passamani
Keyword(s):  
Stray Field ◽  
Superconducting Properties

scholarly journals UPt3: Specific heat, critical fields, and the Ginzburg-Landau models for the superconducting phase diagram

1993 ◽  
Vol 48 (9) ◽  
pp. 6385-6399 ◽  
Author(s):  
T. Vorenkamp ◽  
A. de Visser ◽  
R. Wester ◽  
A. A. Menovsky ◽  
J. J. M. Franse ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Specific Heat ◽  
Superconducting Phase ◽  
Critical Fields ◽  
Ginzburg Landau

SUPERCONDUCTING PROPERTIES OF THE HIGH Tc SUPERCONDUCTING Er-Ba-Cu-O COMPOUND

1989 ◽  
Vol 03 (03) ◽  
pp. 441-444 ◽  
Author(s):  
S. M. M. R. NAQVI ◽  
FIROZ AHMAD ◽  
JAWAID ALAM ◽  
SHARFUDDIN AHMAD
Keyword(s):  
Superconducting Phase ◽  
Superconducting Properties ◽  
X Ray Diffraction ◽  
High Tc ◽  
X Ray ◽  
Zero Resistance ◽  
Two Phases

Two batches of Er-Ba-Cu-O superconductors have been prepared. The zero resistance temperature is 86 K with T c onsets at 99 K and 92 K respectively. Susceptibility measurements show superconducting phase at LN 2. X-ray diffraction results indicates two phases, the superconducting being the major one.

s-Wave holographic superconductor in different ensembles and its thermodynamic consistency

2017 ◽  
Vol 26 (04) ◽  
pp. 1750027
Author(s):  
Lei Yin ◽  
Defu Hou
Keyword(s):  
Order Parameter ◽  
Helmholtz Free Energy ◽  
Canonical Ensemble ◽  
Landau Theory ◽  
Equation Of Motion ◽  
Superconducting Phase ◽  
S Wave ◽  
Holographic Superconductor ◽  
Thermodynamic Relation ◽  
Ginzburg Landau

In this paper, we analytically study the consistency between the Ginzburg–Landau theory of the holographic superconductor in different ensembles and the fundamental thermodynamic relation, we derive the equation of motion of the scalar field which depicts the superconducting phase in canonical ensemble (CE) and a consistent formula to connect the holographic order-parameter to the Ginzburg–Landau coefficients in different thermodynamic ensembles, and we also study the spatially nonuniform Helmholtz free energy.

HIGH QUALITY SmBa2Cu3O7-X THIN FILMS FOR MICROWAVE APPLICATIONS

2003 ◽  
Vol 17 (04n06) ◽  
pp. 768-772 ◽  
Author(s):  
M. A. BOFFA ◽  
F. BOBBA ◽  
A. M. CUCOLO ◽  
R. MONACO
Keyword(s):  
Thin Films ◽  
Microwave Measurements ◽  
Superconducting Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Oxygen Pressure ◽  
Afm Analysis ◽  
Microstrip Resonators ◽  
Microwave Applications ◽  
Critical Current Density Jc

In this paper we report on the analysis of the surface properties of c-axis oriented, highly epitaxial SmBa 2 Cu 3 O 7-X thin films grown by high oxygen pressure d.c. sputtering technique on (100)k LaAlO 3 substrates. Structural and morphological characterizations of the samples were carried out by means of X-Ray diffraction and AFM analysis. The AFM images show a surface morphology with characteristic screw dislocations with roughness of 2-3 nm on 1 μ m 2 area. The superconducting properties indicate a critical temperature Tc(R=0)>90K and a critical current density Jc>1*106A/cm 2 at T=77K. Preliminary microwave measurements on meanderline microstrip resonators show surface residual resistances Rs<13μΩ a 1 GHz at T=4.2K .

Fabrication and Superconducting Properties of High Tc Oxide Wire

1987 ◽  
Vol 99 ◽  
Author(s):  
N. Sadakata ◽  
Y. Ikeno ◽  
M. Nakagawa ◽  
K. Gotoh ◽  
O. Kohno
Keyword(s):  
Critical Current Density ◽  
Liquid Nitrogen ◽  
Liquid Nitrogen Temperature ◽  
Intrinsic Properties ◽  
Superconducting Properties ◽  
Intensive Study ◽  
High Tc ◽  
Fabrication Procedure ◽  
Paper Fabrication ◽  
Critical Current Density Jc

Since the discovery of high Tc superconducting oxide such as Ln-Ba-Cu-O system which shows superconductivity above liquid nitrogen temperature, intensive study has been carried out to investigate its intrinsic properties[l-4]. Superconducting wire which operates in liquid nitrogen is one of the emerging products among application, however, there are many factors to be investigated for practical use. Critical current density, Jc, is one of the most important characteristics of superconductor, although, only few report describing Jc measurement ever published[5]. In this paper, fabrication procedure of silver sheathed Y-Ba-Cu-O wire by powder metallurgical technique and its superconducting properties have been reported. Other factors which may influence superconductivity such as microstructure of the oxide, configuration of wires, etc. are also discussed.

scholarly journals Bulk superconductivity in a four-layer-type Bi-based compound La2O2Bi3Ag0.6Sn0.4S5.7Se0.3

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Rajveer Jha ◽  
Yosuke Goto ◽  
Tatsuma D. Matsuda ◽  
Yuji Aoki ◽  
Masanori Nagao ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Volume Fraction ◽  
Superconducting Phase ◽  
Layered Compound ◽  
Conducting Layer ◽  
Layered System ◽  
Superconducting Properties ◽  
Magnetization Measurements ◽  
Bulk Superconductivity ◽  
Sn Substitution

Abstract Recently, we reported the observation of superconductivity at ~0.5 K in a La2O2M4S6-type (M: metal) layered compound La2O2Bi3AgS6, which is a layered system related to the BiS2-based superconductor system but possesses a thicker Bi3AgS6-type conducting layer. In this study, we have developed the La2O2Bi3AgS6-type materials by element substitutions to increase the transition temperature (Tc) and to induce bulk nature of superconductivity. A resistivity anomaly observed at 180 K in La2O2Bi3AgS6 was systematically suppressed by Sn substitution for the Ag site. By the Sn substitution, Tc increased, and the shielding volume fraction estimated from magnetization measurements also increased. The highest Tc (=2.3 K) and the highest shielding volume fraction (~20%) was observed for La2O2Bi3Ag0.6Sn0.4S6. The superconducting properties were further improved by Se substitutions for the S site. By the combinational substitutions of Sn and Se, bulk-superconducting phase of La2O2Bi3Ag0.6Sn0.4S5.7Se0.3 with a Tc of 3.0 K (Tconset = 3.6 K) was obtained.

Relation of Constituents with Superconducting Characteristics in Low-Temperature-Preheated YBCO Ceramics

1992 ◽  
Vol 275 ◽  
Author(s):  
Junya Nishino ◽  
Hiroaki Nishikawa ◽  
Muneo Ayabe ◽  
Yuji Ikegami
Keyword(s):  
Critical Temperature ◽  
Low Temperature ◽  
Critical Current Density ◽  
Superconducting Properties ◽  
Ybco Bulk ◽  
Disordered Phase ◽  
Yttrium Barium ◽  
Ybco Ceramics ◽  
Critical Current Density Jc ◽  
Critical Temperature Tc

ABSTRACTYBCO bulk ceramics pre-heated at low temperature before sintering were studied on the structure and superconducting properties mainly by varying the concentration of Ba/Y ratio.At 15.8–16.2wt% of the oxygen content Oc calcurated from the compositions of yttrium, barium and copper on the assumption that the valence of copper is 2, (123) phase is main and critical temperature(Tc) and critical current density(Jc) reach to 88–90K and about 103A/cm2, respectively.It is presumed that there is a possibility of the exixtence of oxygen deficient and disordered phase in addition to (123) and (211) phases and BaCuO2.

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