We report the enhanced superconducting properties of double-chain based superconductor Pr2Ba4Cu7O15−δ synthesized by the citrate pyrolysis technique. The reduction heat treatment in vacuum results in the appearance of superconducting state with Tc=22-24 K, accompanied by the higher residual resistivity ratios. The superconducting volume fractions are estimated from the ZFC data to be 50∼55%, indicating

The high-temperature superconducting (HTS) magnetic levitation (maglev) vehicle system is a kind of self-stable levitation mode, which is benefited from the characteristic of flux pinning of non-ideal type II superconductor. And this novel prototype has the outstanding advantages of simple structure, reliable principle, friendly environment and so on. But in the HTS maglev vehicle system, the damping

Superconducting fault current limiter (SFCL), which is used in voltage source converter based high voltage direct current (VSC-HVDC) transmission systems to limit fault currents and protect the grid together with DC circuit breakers, could improve system safety and stability. The first transmission voltage DC SFCL is developed in China, and it has been applied in the 160 kV VSC-HVDC transmission system

The effect of Tl content in TlmBa2Can-1CunO2n+2+δ (TBCCO) superconductor was studied with m=1 and 2, n = 1-4. Samples were prepared using the standard solid-state reaction one-step technique in a sealed quartz tube under normal pressure. The superconductivity was examined using electrical resistance measurements ranging from 300 K to 10 K. The effect of an applied magnetic field (up to 12 T) on the

Iron-based superconductors (IBS) are considered as potential materials for manufacturing high-field magnets, for which developing multi-filamentary conductors with high performance and high strength is essential. Herein, 7-filamentary Cu/Ag composite sheathed Ba0.6K0.4Fe2As2 (Ba122) round wires and tapes were successfully prepared through the ex situ powder-in-tube (PIT) method and treated by hot isostatic

We studied the levitation of a YBa2Cu3O7 (YBCO) melt-textured superconducting specimen above a closed path of permanent magnets. The superconductor was magnetized with an auxiliary permanent magnet before brought to the path of magnets. This way, the superconducting levitation in the mixed state was achieved. The vertical and horizontal forces acting on the superconductor were calculated by means of

In order to realize practical superconducting joints between Bi2223 tapes towards persistent-current magnets, Bi2223 thick films with high critical current density (Jc) suitable for joint intermediate layers are needed. On the other hand, the methodology of c-axis grain alignment for improving the critical current properties in the polycrystalline materials with a relatively large thickness has not

We solve the two-band Ginzburg-Landau equations for a superconducting mesoscopic prism for a condensate characterized by two order parameters (ψ1,ψ2). We study the effect of the phase and γ˜ differences on the vortex state, magnetization, magnetic susceptibility (χm), vortex localization, and vorticity for boths condensate. Finally, we present shown how the vortices form conglomerates in the superconductor

In the present investigation, based on density functional theory computational approach, we show how the experimentally accepted AlB2-like structure of the SrAlGe compound is suggested to be dynamically unstable at 0 K. We propose a stable configuration that is deduced from the detailed analysis of the phonon spectrum with a doubled unit cell and buckled AlGe layers. It allows to closely reproduce

With the increase of DC transmission voltage and capacity, large dc fault current becomes an important issue due to the bottleneck of the capacity of the DC breaker. In order to solve the problem, we have proposed a novel hybrid type DC superconducting fault current limiter (DC SFCL) in our previous papers. Based on a series of previous researches, some improvements are made to design the hybrid type

From the first principles calculation based on the plane-wave pseudopotential method of density functional theory, and the linear response technique, we have performed electronic structure, phonon and electron-phonon interaction of superconducting compounds HfOs and HfRu in B2 phase. The distribution of energy with different wave vector in the first Brillouin zone and conductive charge carriers (electrons

It is generally believed that magnetization measurements on sulfur hydride under high pressure performed in 2015 [1] provided “final convincing evidence of superconductivity” [2] in that material, in agreement with theoretical predictions [3], [4]. Supported by this precedent, drops in resistance that were later observed in several other hydrides under high pressure [2, 5] have been generally accepted

Large-area high-quality MgB2 thin films were needed in many superconducting applications such as superconducting radio frequency (RF) cavities. However, fabricating large films with high quality can be difficult. Thus, a jointing method between MgB2 films can be crucial in a lot of superconducting electronic applications. In this article, we successfully fabricated superconducting joints for MgB2 films

This paper mainly focuses on the development of iron-based superconductor (IBS) coils made by a wind and react method. IBS is brittle after heat treatment, and little mechanical damage may reduce the performance of the tapes and coils. We developed a type of IBS coil with single or double pancake, which exhibits little performance reduction after some technological improvements. High-performance Ba122/Ag/AgSn

A temperature dependence of a width of ΔH=ΔB region has been studied for 5 wt.% (Fe, Ti) particle-doped MgB2 superconductor, which is the region that increased applied magnetic field is the same as increasing magnetic induction in a superconductor. The result revealed that widths of the region are linear along temperature. In this paper, we present meanings of the result and details of the calculation

Fracture of brittle filaments plays a crucial role in significant degradation of critical current density of multifilamentary Nb3Sn strand. Recent researches of distribution of filament factures mostly depend on photographic analysis with SEM or TEM. However, it is hard to obtain spatial distribution of filament fractures in the mulitifilamentary Nb3Sn strand. In addition, almost unavoidable filament

A high-temperature superconducting (HTS) axial flux permanent magnet (AFPM) machine was designed, using superconducting bulks over the rotor surface and rare-earth magnets in the middle of the stator teeth. Because of diamagnetic behavior of the HTS bulks and zero field cooling, leakage flux significantly reduces in the proposed machine compared to the existing machine with mounting rare-earth magnets

When a REBCO tape carrying DC transport current is exposed to a perpendicular AC magnetic field with amplitude above certain value, flux could be triggered to traversing the superconducting tape. During the process, a biased DC response voltage, called the dynamic resistance voltage will be induced. In the paper, the calculation on the time-dependent dynamic resistance voltage was carried out by the

A setup of transverse tension measurements of high temperature superconductor (HTS) RE-Ba-Cu-O coated conductors are modified for simplicity. Modification includes using high strength epoxy films instead of solder as adhesive agents and changing the shape of contact surface between test samples and anvils. This method was designed to measure delamination strength of stabilizer free REBCO coated conductors

A new experimental study by Snider et al. [2020 Nature 586 373–7] reported behavior in a high-pressure carbon-sulfur-hydrogen system that has been interpreted by the authors as superconductivity at room temperature. The sudden change of electrical resistance at a critical temperature and the change of the R vs. T behavior with an applied magnetic field point to superconductivity. This is a very exciting

Intermodulation distortion (IMD) of microwave signals incident upon a superconducting YBa2Cu3O7−x thin film sample on a LaAlO3 substrate is shown to relax as the sample magnetization also relaxes, revealing the signature of fluxon decay in the microwave distortion. The sample contained a microchannel of columnar defects that was introduced using heavy ion beam irradiation. After exposure to and then

A flux transformer, consisting of a superconducting primary loop (pick-up loop) in series with a superconducting secondary loop on which measurement is done, is considered to optimize the approach and sensitivity of the Superconducting QUantum Interference Device (SQUID). Performance of such a pick-up loop placed above a magnetic particle is investigated using the numerical Ginzburg-Landau (GL) simulations

Based on a fully two-dimensional (2D) electrothermal model, the quench propagation characteristics of short superconducting YBa2Cu3O7-x conductors (AMSC and SuperPower), including the minimum quench energy (MQE), normal zone propagation velocity (NZPV) and hot spot temperature rising rate, are studied by numerical simulations in this paper. It is found that different heater configurations, such as

Commercial MgB2 powder manufactured by Alfa Aesar was mechanically sieved in order to obtain powder samples with different particle size. As-sieved powders were used for single-core wires with FeNiCo sheath made by ex-situ process and heat treated at the same conditions, 950 °C/30 min. Resistive transitions of extracted MgB2 cores allowed to obtain the critical temperature and normal state resistivity

Ball milled MgB2 powders and ex situ processed tapes using those milled powders were sintered at various temperatures. Critical temperature (Tc) increases moderately with increasing sintering temperature (Tsin) up to 705 – 735 °C, at which best performance in transport critical current density (Jc) at 4.2 K in 10 T for the tape samples is obtained. In contrast, the Tc rapidly increases when sintered

High-current superconducting conductors are widely used in fusion magnets and high energy accelerators. In order to carry out experimental research on new high-current conductors, we have developed a new test facility for their critical current (Ic) measurements. We have used this facility to test a Nb-Ti Rutherford cable three times. Premature quenches were detected for the first two tests. They were

The design and testing of high current superconducting cables made of ReBa2Cu3O7-z (REBCO) are still under development. It seems to have huge potential to overcome some of the difficulties associated Low Temperature Superconductors. One of the attractive features of CORC® cable compared to other cable types is that a former with a small diameter can be used. This allows a flexible and round wire shape

In order to study the feasibility of the co-transmission of electricity and liquefied natural gas (LNG) based energy fluid, we carried out a project supported by a grant from Chinese national key research and development program, Basic Research on Superconducting DC Energy Pipeline. In this project, a superconducting cable cooled by LNG based mixed energy fluid at temperature around 90 K is proposed

Cross stiffness is usually defined as a change in the vertical force when the levitating body moves a small lateral displacement in a high-temperature superconductor (HTS) magnetic levitation system. In most of the existing research reports, the improvement of the levitation stiffness is usually focused on the radial (lateral) and axial (vertical) stiffnesses. The cross stiffness should be studied

3D integration has well-developed for traditional CMOS technology operating at room temperature, but few studies have been performed for cryogenic applications such as quantum computers. In this paper, a wafer-to-wafer bonding of superconductive joints based on niobium nitride (NbN) is performed to demonstrate the possibility of 3D integration of superconducting chips. The NbN thin films are deposited

We present a strong-coupling study of the competition and interplay between the d-density wave (DDW) and d-wave superconducting (DSC) states within the fluctuation-exchange approximation for the two-dimensional Hubbard model. We find the occurrence of a new DDW state with phase fluctuations induced by spin fluctuations above TC. It is shown that in this state the density of states has a pseudogap,

We investigated the combined effect of flux pinning by three-directional columnar defects (CDs) in a wide field-angular range of YBa2Cu3Oy thin films, where CDs parallel to the c-axis and CDs crossing at ±θi (θi = 45°, 60° and 80°) relative to the c-axis were installed by 200 MeV Xe-ion irradiations. The three-directional CDs with θi ≤ ±60° form a field angular curve of critical current density Jc

In recent years, the design of superconducting electric machines has attracted the attention of researchers and scientists due to the unique properties of high temperature superconducting materials. This paper presents a 20 kW HTS induction motor with a double squirrel cage rotor, in which the HTS and copper bars are embedded in two different slots. The propose of this paper is the investigating of

To study a nonlocal electron transport in an aluminum superconducting quasi-one-dimensional structure, we measured negative nonlocal (local) direct current voltages in the structure in a magnetic field near the critical temperature. The structure is a normal-superconducting at Tcn

We investigate the nonequilibrium pair density wave order parameter in a simple microscopic model with the ground state d-wave spatially uniform superconductivity. After pushing the system out of equilibrium by a short-time induced order parameter, the system can exhibit robust free nondecaying oscillations of nonuniform superconducting order. In the weak nonequilibrium regime, the frequency of these

Motivated by the recent synthesis of Ba2CuO3+δ (BCO), a high temperature superconducting cuprate with putative d3z2−r2 ground state symmetry, we investigated its electronic structure by means of Cu L3 x-ray absorption (XAS) and resonant inelastic x-ray scattering (RIXS) at the Cu L3 edge on a polycrystalline sample. We show that the XAS profile of BCO is characterised by two peaks associated to inequivalent

This paper shows the effect of the Josephson and bi-quadratic coupling types on the vortex state, the magnetization in a two-band superconducting disk in the presence of an external magnetic field and the effect that the γ value has on the vortex state. This study is based on the two bands Ginzburg-Landau time dependent theory, and the main properties are presented via Ab-Initio of MgB2. The superconducting

In this paper, a square central crack problem is investigated for an infinitely long square cross section superconducting column under electromagnetic forces. The generalized Irie-Yamafuji critical current densities model and the magnetically impermeable crack surface condition are adopted for both the zero-field cooling (ZFC) and the field cooling (FC) activation processes. The distributions of magnetic

We observe a hysteretic superconducting switch effect in NbSe2 - CrGeTe3 superconductor/ferromagnet bilayer structures. The switching effect occurs robustly at perpendicular external magnetic fields between 80

In the present study, Mg diffusion process has been investigated by transport measurements and surface morphology analysis in round MgB2 wires made with internal Mg diffusion (IMD) method. These wires were produced using semi-amorphous boron, nano-sized amorphous boron or mixtures of them via cold drawing process. In addition to the conventional IMD wire production technique, a thin layer of magnesium

Based on a model Hamiltonian including the on-site repulsive interaction among the electrons, we investigate the flux-dependent evolution of mixed pairing orders in mesoscopic superconducting square loops by numerically solving the Bogoliubov-de Gennes equations. The influence of centered hole size on the order modulation is mainly discussed. For the emergent spin-triplet p-wave and subdominant spin-singlet

The evacuated tube side-suspended high-temperature superconducting (SS-HTS) magnetic levitation prototype vehicle can run at high speed on a uniform permanent magnet guideway due to the characteristics of magnetic flux pinning. However, permanent magnet guideway with magnetic fluctuations will cause resistance in the running direction of the high-temperature superconducting maglev prototype vehicle

Relation between the binding energy of pair of fermions and the magnitude of the attractive interaction between them is investigated theoretically with the help of mean field approximation, for a two-dimensional (2D) Fermi liquid type superconducting material. Here the fermion pair has finite center of mass momentum (CMM). The fermion pair is considered to be formed in the presence of an active Fermi

In this study, we have constructed an extended version of Ginzburg-Landau theory of superconductivity starting from the exponential non-standard Lagrangian. An extended Ginzburg-Landau coherence length and an extended Ginzburg-Landau parameter emerge in the theory without affecting the Abrikosov's fluxoid quantization law. We have discussed the Abrikosov's periodic vortex lattice problem and we have

In Physical Review Letters 102, 197002 (2009), it was reported that the element Eu becomes superconducting in the pressure and temperature range [84-142GPa], [1.8-2.75K]. The claim was largely based on ac susceptibility measurements. Here I point out that recently reported ac susceptibility measurements on a hydride compound under pressure that appears to become superconducting near room temperature

In this paper, we propose a full-wave analysis for characterizing the resonant frequencies and bandwidths of high-temperature superconductor inverted microstrip printed on anisotropic substrates. Our proposed approach is based on Galerkin procedure in the Fourier transform domain (FTD) combining with the complex resistive boundary condition. With the use of suitable Green's functions in the FTD, the

Growth of single crystals of RuGd-1222 ((Gd,Ce)2Sr2RuCu2O10−δ) remains a major challenge, and previous studies have indicated that epitaxial thin films of these compounds exhibit deteriorated superconductivity. We have been working toward the synthesis of RuGd-1222 single crystals using the self-flux and partial melting techniques. In this paper, we report on the synthesis of RuGd-1222 single-crystal

6+1-filament MgB2 long wires with high critical current densities were fabricated using an internal Mg diffusion (IMD) process. The effect of high temperature treatment by conventional furnace annealing and rapid thermal processing on the superconducting properties and microstructure of IMD wire was investigated. The rapid thermal processing can improve the superconducting properties of multifilament

The AC loss occurred in REBa2Cu3Oy (REBCO, RE = rare earth elements, Y, Eu, Gd) superconductor is serious problem in AC applications because it may cause a severe temperature rise of superconducting systems. Therefore, it is necessary to understand the AC loss property of REBCO superconducting tape in detail and to reduce that. As AC application such as motor, the tape is mostly stacked into multi-layer

Multi-layer insulation (MLI) is a crucial component to reduce a heat leak of a cryostat, and it is used for various applications in cryogenics. Its role is significant for the superconducting power transmission line (SCDC) mainly because the ratio of the surface to the volume is large for the conventional cryostat, and the heat leak is a principal source of the loss of SCDC. If we cannot reduce the

The iron-based superconductor (IBS) is considered to have a great potential application under high magnetic field. It is one of the important steps to carry out the research on high magnetic field IBS inserted coil in order to promote the practical application of IBS. We developed a type of Ba122 single and double pancake inserted coils with 35 mm outer diameter, and its performance has been tested

The main goal of this paper is to obtain the exact quantum solutions for charge space in a superconductor with time-dependent parameters using the London approach. We introduce a new quantization scheme for the charge inside a superconductor based on the Lewis and Riesenfeld invariant operator method. From the wave-functions obtained, we calculated the time-dependent uncertainties and the mean energy

We present a review of the leading theoretical approaches in the field of cuprate high temperature superconductivity. We start out by defining the problem and ask the question: whether an overarching theory possible (which is capable of explaining not only the mechanism of unconventional superconductivity but also a coherent understanding of the strange metal phase and the pseudogap phase)? If it is

In this paper, we investigate a local density of state (LDOS) in a two-dimensional nano-structured superconductor. We solve the Bogoliubov-de Gennes equations self-consistently with the two-dimensional finite element method. In the nano-structured superconductor, the LDOS as a function of energy has many discrete peaks. Discretization of the LDOS comes from discretization of energy levels due to the

The penetration of the magnetic field in a network consisting of the superconducting grains and intergranular region depends not only on the applied external magnetic field but also on the underlying pinning force density and fraction of the superconducting grains in the sample. Considering the underlying pinning force density in the form of the repetitive Gaussian (RG) nature we have solved the critical

The increase of current uniformity along of a Resistive type Superconductor Fault Current Limiter (R-SFCL) in the design of this type of limiters is well perceived as an important issue. The non-uniform distribution of current in R-SFCL only increases the current in some superconducting regions, as a result, in the fault conditions, only certain parts of the superconductor undergo a phase change that

A deep understanding of the quasiparticle inelastic scattering rate in superconducting materials is beneficial for the further development of ultrasensitive and rapid superconducting detectors. From the flux flow instability in current–voltage characteristics of NbN superconducting films, we have derived the critical vortex velocity (ʋ*) and quasiparticle inelastic scattering time (τE) of the 10- and

We have fabricated Nb/Al-AlOx/Nb Josephson junctions and have measured their current-voltage characteristics and the two-dimensional magnetic field dependence of the Josephson current. When the external magnetic fields (Hx, Hy) parallel to the junction plane are applied to the Josephson junction from two directions, two Fraunhofer diffraction patterns are observed in the (Hx, Hy) plane. In this study

A like-CORC based on the Quasi-isotropic (Q-IS) conductor, so called Q-IS_CORC consisting of CORC and Q-IS making from 2 G high temperature superconducting (HTS) tapes, is investigated in terms of AC losses by combining experimental with numerical methods. A new type of a like-CORC conductor is presented and is good bending performance as well as easy to manufacture in long lengths. Moreover, this

Today, superconductor materials are widely used in electric machines because of their unique properties. This has been always a question for designers and researchers whether super-conductors can be a good substitute for Permanent Magnet (PM) or not. In this paper, the performance of a dual stator linear vernier machine under identical conditions in the presence of High-Temperature Superconductor Bulk