High-temperature Superconductor YBa2Cu3O7-δ Research Articles

TMR-high-temperature superconductor composite magnetic sensor and its performance optimization

Tunnel magnetoresistance (TMR), recognized for its high sensitivity and low power consumption, holds significant promise in the domain of weak magnetic field detection. Using superconducting materials as magnetic concentrators can achieve several hundred to even a thousandfold amplification of magnetic fields, making it one of the most effective approaches to enhance the magnetic field resolution of TMR sensors. This paper utilized the flip-chip bonding process to integrate TMR with the high-temperature superconductor YBCO (YBa2Cu3O7-δ), and successfully developed TMR-YBCO composite magnetic sensor. Building upon this foundation, through optimization of the fabrication process and the pioneering use of a structural design incorporating the filling of annular holes with superconducting concentrators, the sensitivity of the sensor was further enhanced. Finally, the magnetic field resolution was increased by 1030 times compared to TMR sensors, reached to 2.9pT/Hz1/2 at 1 Hz. Simultaneously, results from frequency band testing indicated excellent frequency band characteristics, with a frequency response range exceeding kHz.

Orthorhombic YBa2Cu3O7−δ Superconductor with TiO2 Nanoparticle Addition: Crystal Structure, Electric Resistivity, and AC Susceptibility

This article reports the effect of a nanoscale addition of TiO2 on the structure and superconducting parameters of the high-temperature superconductor YBa2Cu3O7-δ (Y123). Polycrystalline compounds of Y123 with different percentages of TiO2, x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0, were fabricated using the thermal treatment method. An analysis using X-ray diffraction confirmed the formation of Y123 phases for all composite samples. Field-emission scanning electron microscopy (FESEM) analysis revealed the growth of grain size and decrease in porosity, with a sign of partial melting of grains for the samples with TiO2 addition. The magnetic and electric transport properties were investigated using AC susceptibility measurement and the four-probe method, respectively. It was observed that the superconducting transition temperature, Tc-onset, for a pure sample determined by ACS and 4PP was 95.6 K and 95.4 K, respectively. These values were found to decrease with the addition of TiO2, while the superconducting transition (∆Tc) improved with TiO2 addition except for the sample at x = 0.2 wt.%, which showed the broadest transition width. The sharpest superconducting transition (∆Tc) was observed for the sample at x = 1.0 wt.%, indicating that the addition of TiO2 nanoparticles is expected to serve as artificial pinning centres and strengthen the connection among the grains in the Y123 ceramic.

Tuning of superconducting phase transition and magnetic properties of ferroelectric-superconducting PbZr0.48Ti0.52O3/YBa2Cu3O7-δ heterostructure

Tuning of superconducting phase transition temperature (Ts) and interfacial magnetism is of great technological importance for micro and nanoelectronics. To achieve the cherished goal, an ultra-thin layer (4 nm, 6 nm, 8 nm 10 nm) of ferroelectrics PbZr0.48Ti0.52O3 (PZT) on high-temperature superconductor YBa2Cu3O7-δ (YBCO) has deposited to tailor the magnetic and superconducting properties. The existence of Meissner effect confirmed the superconducting nature of YBCO in the heterostructures. However, its Ts significantly shifted to the lower temperature side with an increase in PZT capping layers' thickness. Nearly 10 K reduction in Ts was observed with an increase in the capping layer from 4 to 10 nm. A significant amount of magnetic moment was found in the heterostructures, which increases almost three times compared to the YBCO/LAO magnetic moment above Ts. We believe novel weak magnetic phases above the Ts may be due to the re-arrangement of oxygen anion near the ferroelectric-superconducting interface.

Measurements of phase shifts in YBCO transmission lines for evaluation of kinetic inductance change

We fabricated a coplanar waveguide (CPW) using high temperature superconductor YBa2Cu3O7-δ (YBCO) and evaluated its characteristics for the realization of a superconducting parametric amplifier. A YBCO thin film with a film thickness of 200 nm was formed by the PLD method using a YAG laser on a 10 × 10 mm MgO substrate. The YBCO thin films were processed into the CPW shape with a line width of 8 μm, a gap width of 8 μm and a line length of 5 mm by photolithography and sputter etching. Using a network analyzer, phase differences of microwave were measured at dc current bias from 0 mA to 14 mA. From the measurement results, it was found that the phase difference decreased with increasing temperature. In addition, it was found that the phase shifts greatly varied near the superconducting transition temperature at each current bias. We observed a maximum phase difference Δθ of -0.08 rad at a bias current of 14.0 mA, which is the closest to the transition temperature. A parametric gain was estimated to be 0.15 dB from the measured maximum phase difference.

Effect of colossal magnetoresistance material La0.67Ca0.33MnO3 on superconducting properties of YBa2Cu3O7-δ thin films

Abstract By specific design of the sample, in which SrTiO3 substrate is fully covered by a thin layer of the colossal magnetoresistive material La0.67Ca0.33MnO3 (LCMO) and the latter is partially covered by high-temperature superconductor YBa2Cu3O7-δ (YBCO), and by using multiple current and voltage contacts, direct evidence of the strong effect of LCMO on YBCO is obtained. It is found that LCMO strongly influences not only superconducting, but also normal state of YBCO, and it is argued that this is a consequence of the spin injection from the former to the latter. The effect of the deposition conditions and crystal orientation of YBCO layer on this effect is clarified. A surprising peak in the temperature dependence of resistance seen in ex-situ ab-plane oriented sample is explained as a combination of two effects: influence of spin-polarized electrons on superconductor below its critical temperature and the interface-controlled shift of Curie temperature of LCMO to low temperatures. Considering expected use of LCMO and YBCO in composite quantum computation circuits, their combination with another advanced quantum material, graphene, is explored.

Effects of CNTs blending on the superconducting parameters of YBCO superconductor

We report the structural modifications and variation of superconducting parameters of high temperature superconductor (HTSc) YBa2Cu3O7-δ (YBCO) by addition of different wt% of CNTs (0.0, 0.2, 0.4, 0.6, 0.8 & 1.0 wt%) synthesized by standard solid state reaction route. The orthorhombic structure of all the samples with Pmmm space group was confirmed from the X-ray Diffraction (XRD) analysis through Rietveld refinements. No significant variation is observed in the lattice parameters of the orthorhombic structure of YBCO superconducting matrix with increasing wt% of CNTs. The Field emission scanning electron microscope (FESEM) analysis shows better connectivity between the grains of CNTs doped samples. From the temperature dependent resistivity measurement, it is observed that there is no chemical reaction between superconducting YBCO and CNTs, rather addition of CNTs enhances the room temperature resistivity and more importantly reduces the critical temperature (TCon) for lower doped sample and then increases for higher doped sample but not for the pristine one. The paraconductivity studies reveal the 2D-3D transition in parent YBCO and the composites, with a signature of percolative behavior in the composites. Inclusion of CNTs to the YBCO enhances the value of critical current density and gives maximum value of JC which is 12 times more than that of pure YBCO sample for 0.8 wt% of YBCO.

Replacement of NbN by YBa2Cu3O7-δ in superconducting thin film coil in a spiral trench on a Si-wafer for compact SMESs

To improve the energy storage volume density of our concept of a compact superconducting magnetic energy storage system, replacement of superconducting material NbN for the thin film coil in the spiral trench on a Si wafer by a high temperature superconductor YBa2Cu3O7-δ was addressed. By using the successful result previously reported to grow a c-axis oriented film on a steel substrate, a superconducting film of Tc=45.5 K was obtained using similar buffer layers including a (100) oriented CeO2 layer over a (100) oriented YSZ layer. The similar result reported on a SrTiO3 single crystal substrate without any buffer layers indicates c-axis oriented film of Tc=90K can be obtained by further reduction of oxygen partial pressure.

The Berezinskii-Kosterlitz-Thouless phase transition in the Josephson medium of a two-level granular high-temperature superconductor YBa2Cu3O7-δ

The temperature dependences ρ(T) of the electrical resistivity of the granular high-temperature superconductor YBa2Cu3O7-δ are measured in different transverse external magnetic fields 0 ≤ Hext ≤ 100 Oe for temperatures ranging from the temperature Tρ=0 at which resistivity appears to the critical superconducting transition temperature Tc and transport current densities ranging from 50 to 2000 mA/cm2. The effects of temperature, external magnetic field, and transport current density on the kinetics of phase transitions in both subsystems of the granular HTSC are studied. The possibility of a topological phase transition—a Berezinskii-Kosterlitz-Thouless phase transition in a Josephson medium—is established and the conditions for its occurrence are studied.

Fabrication of Superconducting YBCO Nanoparticles by Electrospinning

High temperature superconductor YBa2Cu3O7-δ (HTS YBCO) nanoparticle was successfully prepared by electrospinning and sol-gel techniques. The sol-gel containing a homogeneous solutions of the precursor of Y-Ba-Cu acetate and Poly (vinyl pyrrolidone) PVP. The critical transition temperature (Tc) of the samples have been found using four point probe technique. By optimizing electrospinning, sol-gel process and heat treatment procedure, YBCO nanoparticle with a transition temperature of 78K was obtained. The surface area measurements of YBCO samples showed, high surface area 2.0 m2/g for nanoparticle, in comparison with block sample 1.0 m2/g. The structural Characterizations of YBCO samples demonstrated that, the YBCO nanoparticles have single phase orthorhombic structure which typical crowd nanoparticles diameter were 388nm. The Individual nanoparticle diameter were found between 20 and 50nm. The calcination temperature at 950 oC does not affect to decrease the surface area of YBCO samples. Electrospinning in combination with a sol-gel techniques are an effective routes to realize different nanostructure morphologies of YBCO superconductor. Production of HTS YBCO nanoparticle by these process promising practical applications.

Strong vortex matching effects in YBCO films with periodic modulations of the superconducting order parameter fabricated by masked ion irradiation

We report on measurements of the magnetoresistance and of the critical current in thin films of the high-temperature superconductor YBa2Cu3O7-δ (YBCO). A square array of regions with suppressed superconducting order parameter has been created in these films by introducing point defects via irradiation with He+ ions through a silicon stencil mask. In such a structure distinct peaks of the critical current can be observed at commensurate arrangements of magnetic flux quanta with the artificial defect lattice. Concurrently, the magnetoresistance shows pronounced minima. Both observations demonstrate that the strong intrinsic pinning in YBCO can be overcome by a periodic array of ion-damage columns with 300nm spacing.

The Effect of Different Salt Additions on the Microstructure of YBCO Synthesized by a Biomimetic Method

The effect of different salt additions on the granular microstructure of samples of the high temperature superconductor YBa2Cu3O7δ (YBCO) synthesized by a biomimetic method has been investigated. Attempting biotemplating using salts with the rock-salt structure, most such salts were found to be chemically compatible with the YBCO biosynthesis, but only NaCl and KCl were observed to result in the desirable strongly anisotropic platelet growth to form clusters with localized orientational alignment. Broadening the range of additions to other chloride salts of varying structures resulted in an increase in the CuO impurity content of the samples, but with all the YBCO formed exhibiting platelet growth. Chloride salts are therefore considered to be good candidates for addition to the biomimetic YBCO synthesis in order to achieve anisotropic platelet growth.

Study of the Effect of Oxygen Annealing on YBCO Platelet Aggregates Synthesized by a Biomimetic Method

The effect of different oxygen annealing treatments on the structural and electrical properties of samples of the high temperature superconductor YBa2Cu3O7δ(YBCO) synthesized by a biomimetic method has been studied. By oxygen annealing, the oxygen deficiency resulting from the synthesis in air can be adequately compensated. A two-stage annealing process including a high temperature step results in a sharper superconducting transition and higher critical current density of the YBCO than annealing only at low temperature, due to the additional elimination of carbon residues from the biopolymer additive. To avoid the formation of impurity phases resulting from decomposition of the YBCO during the high-temperature anneal, careful pre-treatment by rinsing the as-synthesized YBCO with distilled water to remove residual NaCl is necessary.

Addition of Iridium to the Biopolymer Mediated Synthesis of YBa2Cu3O7 δ

Abstract This work represents the first study into the addition of iridium into the solgel synthesis of the high temperature superconductor YBa2Cu3O7δ (Y123). Through a biopolymermediated synthetic approach, the homogeneous nature of the precursor sol and the preferred nucleation and growth of Y123 phases allow for a high yield of superconducting nanoparticles with no suppression of the superconducting critical temperature, even at high levels (40 wt%) of iridium addition. We attribute this to iridium not substituting into the Y123 crystal lattice, instead forming an associate phase.

Positron Annihilation Lifetime Spectroscopy Study of Neutron Irradiated High Temperature Superconductors YBa2Cu3O7-δ for Application in Fusion Facilities

This study focuses on the crystallographic defects introduced by neutron irradiation and the resulting changes of the superconducting properties in the high temperature superconductor YBa2Cu3O7-δ. This material is considered to be most promising for magnet systems in future fusion reactors. Two different bulk samples, pure non-doped YBa2Cu3O7-δ (YBCO) and multi-seed YBa2Cu3O7-δ doped by platinum (MS2F) were studied prior to and after irradiation in the TRIGA MARK II reactor in Vienna. Neutron irradiation is responsible for a significant enhancement of the critical current densities as well as for a reduction in critical temperature. The accumulation of small open volume defects (<0.5 nm) partially causes those changes. These defects were studied by positron annihilation lifetime spectroscopy at room temperature. A high concentration of Cu–O di-vacancies was found in both samples, which increased with neutron fluence. The defect concentration was significantly reduced after a heat treatment.

Textured YBaCuO Films Enhanced by Cold Rolling and Melt Growth Process in Low Oxygen Partial Pressure

High critical current density Jc under high magnetic field is required in numerous applications for high temperature superconductor YBa2Cu3O7-δ (Y123). Significant efforts have been made to control sample preparation in view of optimized textures and microstructures. In YBa2Cu3O7-δ superconductor, Jc is limited by grain misalignment and by other defaults like secondary phase (Y211), microcracks... So YBaCuO films were prepared by electrophoretic deposition directly on polycrystalline Ag substrate. Melt textured growth (MTG) in low oxygen partial pressure and cold rolling were performed to YBaCuO samples respectively to improve texture growth of the films and to study deformation effect on the texture. The film obtained by melted growth after rolling has better texture orientation than the film without rolling, and presents higher critical current density.

On the new universal possibility to detect phase transitions in correlated electron systems

We investigate temperature and concentration driven phase transitions (structural and reentrant phase transitions included) in magnetic and superconducting systems with the use of a wide class of model Hamiltonians applied to rare earth (Re) based compounds and alloys (integer and fluctuating valence systems). Studying the temperature or concentration dependence of the chemical potential we observe small but distinct and well localized kinks at all critical points as evidence for phase transitions. For systems with, at least, two kinds of interacting electrons the kinks at critical temperatures or concentrations occur also in the electronic average occupation numbers (critical electron redistribution). These observations suggest a direct and universal experimental application of the chemical potential as a detector of phase transitions for temperature and concentration driven phase transitions, as well as, for pressure-or external field-induced transitions in solids. The agreement between the calculated critical temperature behaviour of the chemical potential, presented in this paper, and experimental measurements for high-temperature superconductor YBa2Cu3O7-δ entirely supports these general observations.

Transmission electron microscopy and high-resolution transmission electron microscopy studies of the early stages in the degradation of yba2cu3o7-δsuperconductor in water vapour

Abstract The initial stages of water vapour attack of the high-temperature superconductor YBa2Cu3O7-δ have been studied by transmission electron microscopy (TEM). The planar defects both of thickness 0·2 nm and of thickness 0·4 nm reported previously have been observed. The defects are sometimes associated with preexisting sites of strain in the material, but such strain is certainly not required for their nucleation, since often they occur in initially perfect material. A model for the thinner defect has been developed, which fits well with the TEM observations, as well as with bond valence calculations and previous work on the degradation of YBa2Cu3O7-δ by water. The implications of the model for that degradation process are discussed.

Strong coupling, fluctuations and the specific heat of YBa2,Cu3O7-δ

Abstract Specific-heat data on the high-temperature superconductor YBa2Cu3O7-δ provide evidence for strong coupling. The data on ceramic and single-crystal samples also indicate that, when there is a fluctuation contribution to the specific-heat anomaly at Tc' the anomaly is reduced in height. These results are consistent with the idea that an oxygen deficiency reduces γ and enhances fluctuation effects.

Local non-stoichiometry in superconducting and ferroelectric films of complex oxides

Abstract By analogy with ferroelectric deposits, in films of deposited high-temperature superconductor YBa2Cu3O7-δ there have been found surface and interface (film-substrate) layers, having a modified composition with respect to the main layer and different charge state of the constituent ions. However, in contrast to the ferroelectric films of BaTiO3 type, the specific habitus of microcrystals in the YBa2Cu3O7-δ films favours the formation of oriented layers already at the stage of annealing of the initially quasi-amorphous deposits, the stoichiometry of the main layer being preserved. Deterioration of the properties of the films on buffer layers may be explained by changes in the charge state of the film and substrate ions.

ChemInform Abstract: Crystal Growth and Characterization of the High Temperature Superconductor YBa2Cu3O7‐δ

ChemInformVolume 21, Issue 30 Reviews ChemInform Abstract: Crystal Growth and Characterization of the High Temperature Superconductor YBa2Cu3O7-δ F. HOLTZBERG, I. B. M. Res. Div., T. J. Watson Res. Cent., Yorktown Heights, NY 10598, USASearch for more papers by this authorC. FEILD, I. B. M. Res. Div., T. J. Watson Res. Cent., Yorktown Heights, NY 10598, USASearch for more papers by this author F. HOLTZBERG, I. B. M. Res. Div., T. J. Watson Res. Cent., Yorktown Heights, NY 10598, USASearch for more papers by this authorC. FEILD, I. B. M. Res. Div., T. J. Watson Res. Cent., Yorktown Heights, NY 10598, USASearch for more papers by this author First published: July 24, 1990 https://doi.org/10.1002/chin.199030318Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume21, Issue30July 24, 1990 RelatedInformation