YBaCuO Bulk Superconductors Research Articles

Fabrication and properties of nano-CeO<sub>2</sub> doped Y-Ba-Cu-O bulk superconductors

Single-domain Y-Ba-Cu-O (YBCO) bulk superconductors can be widely used in the superconducting maglev, cryomagnets, motors/generators fields. In order to improve the performance of the YBCO bulk superconductors further, in this work, nano-CeO<sub>2</sub> doped YBCO bulk superconductors are fabricated by two infiltration growth techniques (011-IG and 211-IG) respectively, in which two solid pellets of compositions Y<sub>2</sub>O<sub>3</sub>+1.15BaCuO<sub>2</sub>+0.1CuO+1wt.% nano-CeO<sub>2</sub> and Y<sub>2</sub>BaCuO<sub>5</sub> (Y-211)+1 wt.% nano-CeO<sub>2</sub> are employed. And a novel pit-type seeding mode is used to prevent the film seed from moving in the heat treatment process, then the growth morphologies, microstructures and superconducting properties of the samples are investigated. The results show that at a low doping level (1 wt.%), the normal growth of the YBCO crystal is not affected, and fully-grown single-domain YBCO bulk superconductors can be successfully prepared by the two techniques. Furthermore, the positions of the seeds do not move at all, which proves the effectiveness of the new seeding mode. The perpendicular growth sector boundaries on the top surfaces of the samples and clear (00<i>l</i>) series X-ray diffraction (XRD) peaks both prove the high <i>c</i>-axis orientations and high growth quality of the samples. The scanning electron microscopy (SEM) results indicate that the nano-CeO<sub>2</sub> doping can effectively refine the sizes of the Y-211 micro-particles in the bulk superconductors, and this method is applicable to both techniques. Low-temperature magnetization measurement shows that the nano-CeO<sub>2</sub> doped sample prepared by the 011-IG method shows obviously better <i>J</i><sub>c</sub> property than the undoped sample at low fields, indicating that the refined Y-211 particles can effectively enhance the δ<i>l</i>-type pinning. In addition, compared with the 211-IG-processed sample, the 011-IG-processed sample performs better in terms of levitation force, microstructure and <i>J</i><sub>c</sub> property, thus the 011-IG method is a more promising preparation process. The results of this study are important in improving the performance of the YBCO bulk superconductors and optimizing the fabrication technique further.

The influence of porosity on the superconducting properties of Y–Ba–Cu–O single grains

The trapped field in Y–Ba–Cu–O (YBCO) bulk single grain superconductors correlates directly with the critical current density J c, which, in turn, is dependent on the microstructure of the bulk material. It has been shown recently and indirectly that porosity influences J c of these technologically important materials, in addition to the presence of well-researched Y2BaCuO5 (Y-211) particles in the bulk sample. In this work, we report the direct impact of porosity on the critical current density of a single grain YBCO bulk superconductor using 3D x-ray computer tomography scans and superconducting quantum interference device measurements. It is concluded that porosity has a considerably more substantial impact on the measured critical current density than Y-211 on the micrometre scale with, predictably, a decrease in porosity leading to an increase in J c. J c is directly proportional to the trapped field, so any method that can reduce porosity, therefore, improves J c, and, subsequently, the trapped field of these technologically important bulk superconductors.

Effect of partitioning YBaCuO bulk on the levitation force in Halbach external field

When a YBaCuO bulk superconductor (SC) is subdivided, its levitation force may not be significantly reduced after this partitioning process. The force will decrease even less if the sectional surface introduced by partitioning is parallel to the induced current loop. Moreover, the levitation force can be maintained because the partitioning makes the SC more magnetizable. These findings have implications for longitudinal maglev technology. A method for calculating levitation forces in nonuniform fields based on critical-state theory is proposed. In this method, an SC is divided into several regions where the external field is approximately uniform within each subvolume. To minimize the force degradation introduced by partitioning, the cutting surfaces should be parallel to the induced current. This approximate approach can effectively reproduce the experiment and improve the calculation accuracy. Another application of combining and recovering discrete SCs is demonstrated, and it is shown that a recombined SC according to the small-loss partitioning condition can achieve 68% of the levitation capacity of an intact sample. In addition, the invisible cracks inside the bulk sample can be predicted by comparing its levitation force with that of the intact sample.

The magnetic and levitation characteristics of single-grain YBaCuO and GdBaCuO-Ag bulk superconductors in high magnetic fields

In principle, high-temperature superconducting (HTS) flux-pinning maglev has the advantage of self-stable levitation and is therefore a good development prospect as a new rail transit technology. The magnetic field intensity is one of the key factors affecting the levitation performance of single-grain bulk superconductors in the HTS maglev system. To date, however, most researchers have focused on the levitation performance of HTS bulk superconductors in magnetic fields within a permanent magnet guideway (PMG) configuration. The magnitude of the external working magnetic field provided by a PMG is limited to about 0.5 T at 77 K, given that the superconductor usually levitates at a typical working height of 10 mm above the PMG. Therefore, the weak magnetic fields generated by the PMG significantly limits the levitation performance of HTS maglev systems to that of the permanent magnet (PM). In this article, a superconducting magnet test bench was utilized to provide a 0–3 T external magnetic field (B) environment for the study of the levitation force in HTS single grains. The difference in levitation performance between YBaCuO (YBCO) and GdBaCuO-Ag (GdBCO-Ag) bulk superconductors under large, changing magnetic fields was studied systematically. The relationships between levitation force and magnetic field characteristics, including vertical magnetic field component (Bz), transverse magnetic field component (Br), and vertical magnetic field variation (ΔBz) were investigated. The result of variation curves about YBCO and GdBCO bulks' levitation forces under different ΔBz shows that the levitation force of the bulk, single-grain superconductors will reach saturation under a varying ΔBz environment (0.72 and 1.5 T). The values of ΔBz corresponding to the saturation positions are found to be independent of the sizes of the HTS samples. At the same time, GdBCO-Ag exhibits a levitation force that is 112.8% greater than YBCO in B = 3 T magnetic environment. As a result, it is demonstrated that the levitation potential of single-grain HTS bulks can be better exploited by optimizing the distribution of the magnetic field.

Magnetic force and stiffness performances of Maglev system based on multi–surface arrangements with three-seeded bulk YBaCuO superconductors

We have designed a multi–surface HTS (high temperature superconductor with three seeded bulk YBaCuO) Maglev system by increasing the YBaCuO number while decreasing the PM number in HTS–PMG system to enhance the loading capacity and stability of the superconducting Maglev system while reducing the fabrication cost. By this study, a detailed investigation on the magnetic levitation force, guidance force, magnetic stiffness and cost analysis of the multi–surface HTS Maglev system has been carried out for the first time. In this study, it is determined that the multi–surface YBaCuO–PMG arrangements are superior to the single–surface arrangements with respect to the loading capacity and especially the movement stability of Maglev systems together. Additionally, it is seen that the using of the multi–surface YBaCuO–PMG arrangement reduces the fabrication cost of the Maglev systems as 42.0% for 1000 km magnetic rail while increasing of the levitation force efficiency as 43.4% and this emphasizes the advantage of multi–surface arrangements to the classical single–surface ones. The obtained results can contribute to the researchers working on Maglev and have a capability to increase the usage potential of Maglev systems in commercial applications because of both the loading capacity and stability of Maglev systems can be enhanced together with reducing the fabrication cost without any loss in levitation performance.

Vertical–Lateral Coupling Force Relation of the High-Temperature Superconducting Magnetic Levitation System

A high-temperature superconducting (HTS) magnetic levitation (maglev), based on YBaCuO bulk superconductors and permanent magnet guideways, shows the potential to be applied in the future rail transportation. The maglev forces (levitation and guidance force) of the HTS maglev system, which bond the vehicle and the guideway, are the key factors of its dynamics studies. In practical operation, the HTS maglev vehicle moves in both the vertical and lateral directions, but the previous force models are in single degree of freedom. In this article, an experiment was designed to study the vertical-lateral coupled effect of the levitation and guidance force. A 2-D coupling model was proposed to fit the experimental data. Furthermore, the motion stability and the dynamical characteristics of the HTS maglev system in 2-D space were studied. The simulation results show that the vertical-lateral coupling effect in maglev forces cannot be neglected, and one direction motion can affect the motion in the other direction. It also shows that the proposed force model is suitable for HTS maglev dynamics' calculations.

Magnetic Properties of YBaCuO Superconductors Fabricated Using Melt Growth

YBa2Cu3O7–y (YBaCuO) superconductors used in energy storage devices are superconducting permanent magnets in bulk form. YBaCuO bulk superconductors are fabricated by interior seeded melt growth. Because the seed crystal growth is based on a slow diffusion reaction, long-term heat treatment is required to fabricate a single crystal in order to improve the magnetic properties of the bulk YBaCuO superconductor. We fabricated a single-grain bulk YBaCuO superconductor by controlling the distance between the seed and the upper surface of the YBaCuO bulk. The magnetic levitation force and trapped magnetic field were measured for the YBaCuO superconducting bulk. The correlation between the superconducting magnetic properties of the specimens and the microstructure of each crystallographic plane were evaluated.

Superconducting Properties of YBaCuO Bulk Superconductors

The use of a high-temperature superconductor to manufacture products for commercialization requires a superconductor with a flexible function designed to meet the characteristics of each product. Appropriate mechanical properties need to be maintained to overcome the Lorenz force generated under high magnetic fields. Several studies focused on the improvement of superconductivity and the development of processing technology. However, high temperature superconductivity wires are not intended for large-scale applications at liquid nitrogen temperature (77 K). Recently, ceramic superconductors have been fabricated into bulk and thin films or wire rods for electric power applications; however, ceramics are hard to deform due to increased hardness, which is one of the biggest limitations of a superconductor, and a major obstacle to industrial applications. To overcome these limitations, a synthetic method for superconductivity to reduce the hardness of ceramic superconductor and prevent its degradation was proposed for applications such as superconductivity power cables and wires in energy and electric machines using superconductors.

Magnetic levitation and guidance performance of Y–Ba–Cu–O and Gd–Ba–Cu–O bulk superconductors under low ambient pressure

The high-temperature superconducting Maglev-evacuated tube transport (HTS Maglev-ETT) system has significant potential for practical applications. In order to employ HTS bulks in an ETT system, it is necessary to study the magnetic levitation and guidance performance of bulk superconductors under low ambient pressure conditions that are representative of those inside the tube. As a result, we have investigated the Maglev performance of Y–Ba–Cu–O (YBCO) and Gd–Ba–Cu–O (GdBCO) single grain, bulk superconductors under different ambient pressures of 100 kPa, 60 kPa and 20 kPa using a bespoke pressure-controlling platform, in which the superconductors were positioned above a Halbach permanent magnet guideway. The levitation forces under conditions of field-cooling (FC) and zero-field-cooling (ZFC) have been measured and analyzed. The guidance force for the FC case and the levitation force relaxation for the ZFC case were also measured. It was found from the experimental results that the Maglev performance of both types of bulk superconductor improves significantly by reducing the ambient pressure in their immediate working environment. The levitation forces of YBCO and GdBCO bulk superconductors were observed to increase by 11.6% and 4.4% in the case of FC, and by 20.3% and 13.7% in the case of ZFC, respectively, as the ambient pressure changed from 100 kPa to 20 kPa. An improvement of the guidance force and an inhibition of the levitation force relaxation were also observed for these materials. The supercooled liquid nitrogen cryogen in the low-pressure environment further reduces the temperature, which, in turn, increases the critical current density Jc of the bulk superconductors and improves their levitation performance. These results provide further evidence of the significant advantages of combining HTS Maglev with evacuated tube technologies as a key enabling feature of the HTS Maglev-ETT system. The data further indicate that YBCO bulk superconductors tend to be more sensitive to ambient pressure and temperature variation than GdBCO bulk superconductors. This difference essentially reflects the dependence of Maglev performance of HTS bulk superconductors on Jc when operating in a low-pressure environment.

Synthesis of Y2BaCuO5 nano-whiskers by a solution blow spinning technique and their successful introduction into single-grain, YBCO bulk superconductors

The ability of single grain Y-Ba-Cu-O (YBCO) bulk superconductors to trap large magnetic fields is due generally to the presence of embedded, non-superconducting Y2BaCuO5 (Y-211) phase particles, in optimum amount, in the superconducting YBa2Cu3O7-δ (Y-123) phase matrix, which increases flux pinning and, hence, critical current density of the bulk material. The presence of smaller particles of Y-211 could be expected to improve further the superconducting properties of single grain, bulk YBCO samples, although the smallest Y-211 particles that have been engineered to date within the bulk microstructure are around 800 nm in size. It is extremely challenging to reduce the Y-211 particle size any further due to problems of particle agglomeration that originate, inevitably, from the effects of surface energy and reactivity at relatively high processing temperatures. In this work, we report a novel approach to the fabrication of Y-211 pinning centres in bulk YBCO superconductors in the form of nano-whiskers manufactured by a solution blow spinning technique. The Y-211 nano-whiskers, of which 62% were smaller than 500 nm, were added to the YBCO precursor powders to produce a single grain bulk sample by the buffer-aided top-seeded melt growth (BA-TSMG) processing technique. The resulting YBCO single grain, of diameter 20 mm, was able to trap a magnetic field of 0.63 T at 77 K with an associated critical current density of 3.9 × 104 A/cm2 in self-field. The results of this study demonstrate clearly that the use of Y-211 nano-whiskers is a promising route for enhancing flux pinning in bulk YBCO single-grains, which is potentially significant for the development of high field engineering applications.

Clean Bulk YBaCuO Superconductors Doped by Paramagnetic Ions of Sm and Yb

Clean Bulk YBaCuO Superconductors Doped by Paramagnetic Ions of Sm and Yb

YBCO Bulk Superconductors with Sm Addition

The influence of Sm addition on the microstructure and superconducting properties of Y-Ba-Cu-O (YBCO) bulk superconductors has been studied. Precursor powders YBa2Cu3O7-δ (Y-123), Y2O3 and CeO2 were enriched with different amounts of SmBa2Cu3Oy (Sm-123) or Sm2O3 powders with the aim to increase critical current density, Jc,by introducing additional pinning centers. YBCO bulk superconductors with SmBa2Cu3Oy (Y123-Sm) or Sm2O3 (Y123-SmO) powder addition were prepared by the optimized top seeded melt growth process in the form of single grains. Microstructure analysis revealed that Sm2O3 addition leads to a higher amount of smaller Y2BaCuO5 (Y-211) particles, what is related to high critical current densities (Jc ~ 7 x 104 A/cm2) of the YBCO samples with Sm2O3 addition in low magnetic fields. The effect of Sm addition in the form of SmBa2Cu3Oy as well as Sm2O3 powder on Y2BaCuO5 particle size, critical temperature, Tc, and critical current density, Jc, is reported.

Enhancement of trapped field in single grain Y–Ba–Cu–O bulk superconductors by a modified top-seeded melt-textured growth

The modified top-seeded melt-textured growth technique for fabricating single grain Y–Ba–Cu–O (YBCO) bulk superconductors with high field-trapping ability by using modified precursor pellets was reported. The modified precursor pellets are composed of different precursor powders YBa2Cu3O (Y123) + x mol% Y2BaCuO5 (Y211) + 1 wt% CeO2 without any further chemical doping. The modified YBCO bulks up to 25 and 34 mm in diameter were successfully fabricated from the modified precursor pellets. Microstructural observation results showed that the modified YBCO bulk exhibited a homogeneous distribution of Y211 phase particles, which was qualitatively explained by the solute diffusion growth model in combination with the trapping/pushing theory. As a result, it is notable that the peak trapped field values of 0.91 T (maximum 0.96 T) and 1.2 T (maximum 1.28 T) at 77 K were achieved for 25 and 34 mm modified YBCO bulks, respectively. In a word, the results from present work are very helpful to understand the melt growth mechanism and to further improve the properties of YBCO bulk superconductors for practical applications.

Microstructure and Superconducting Properties of YBCO Bulk Superconductors With RE Substitutions

The influence of RE ( $\text{RE} = \text{Yb}, \text{Sm}$ ) substitutions on the microstructure and superconducting properties of Y-Ba-Cu-O (YBCO) bulk superconductors has been studied for different RE concentrations and their combinations. Precursor powders $\text{YBa}_{2}\text{Cu}_{3}\text{O}_{7-\delta}$ (Y-123), Y2O3 and CeO2 were enriched with different amounts of Yb2O3 and (or) Sm2O3 powders with the aim to increase critical current density, i.e., $J_{c}$ , in self-field as well as in higher magnetic fields, by introducing additional pinning centers. YBCO bulk superconductors with RE2O3 addition were prepared by the optimized top-seeded melt-growth process in the form of single grains. Microstructure analysis revealed that RE2O3 addition leads to a higher amount of smaller Y2BaCuO5 (Y-211) particles, which is related to high critical current density $(J_{c} \sim 7 \times 10^{4} \text{A/cm}^{2})$ of the samples with RE2O3 addition in low magnetic fields. In this paper, the effect of RE2O3 addition on Y-211 particle size, critical temperature $T_{c}$ , and critical current density $J_{c}$ is reported.

A modified multi-seeding approach for YBCO bulk superconductors using Y2BaCuO5 buffer process

We reported a modified multi-seeding approach to grow multi-seeded single grain Y–Ba–Cu–O (YBCO) bulk for overcoming the problem in conventional multi-seeding method, i.e. the existence of residual impurity phases (unreacted liquid phases and segregated RE2BaCuO5 phases) at the grain boundaries in the multi-seeded YBCO bulk. By inserting an Y2BaCuO5 (Y211) buffer between SmBa2Cu3O7−δ (Sm123) seeds and YBa2Cu3O7−δ (Y123)/Y211 compact, the multi-seeded YBCO bulk samples with Y211 buffer were grown successfully. A single peak of trapped field distribution with enhanced trapped field value can be observed in multi-seeded YBCO bulk sample with Y211 buffer. Microstructural studies show that the extent of residual impurity phases deposited at the grain boundary of the multi-seeded YBCO sample with Y211 buffer is significantly decreased compared with that of sample without Y211 buffer, which indicates that the buffer process is effective in decreasing the excluded phases formed at the grain boundaries in the multi-seeded bulk superconductor. The considerably suppression of the residual impurity phases can be qualitatively explained by the proximity effect of the seeds which is caused by the new buffer growth process similar to the seeded infiltration and growth (SIG) combined with the top seeded melt growth (TSMG).

Influence of layered precursor pellets on the growth and properties of Y-Ba-Cu-O bulk superconductors by top-seeded melt-textured growth

It is well known that a fine and homogeneous distribution of Y2BaCuO5 (Y211) phase particles in single-grain Y-Ba-Cu-O (YBCO) bulk superconductors is essential for improving field-trapping ability. However, the size and concentration of Y211 phase particles in the fully melt-processed superconducting bulk increase significantly with the distance from the seed, which results in the accumulation of Y211 phase particles and the degradation of superconducting properties. In this paper, we report a new method of fabricating single-grain YBCO using layered precursor pellets. Using the top-seeded melt-textured growth process, single-grain YBCO bulk superconductors of about 22 mm in diameter and 9 mm in thickness were fabricated from layered precursor pellets and standard precursor pellets, respectively. The layered precursor pellets consist of precursor powders with 40 mol% Y211 at the top, 30 mol% Y211 in the middle and 20 mol% Y211 at the bottom of the whole pellets, while standard precursor pellets are prepared from precursor powders with only 40 mol% Y211. The growth morphology, microstructure and magnetic flux properties of the layered samples and standard samples were comparatively studied. The results proved that the layered precursor pellets allow a sufficient growth in the c-growth sector and a more uniform distribution of the Y211 phase in the matrix. The distribution of Y211 phase particles is qualitatively explained by the prevalent trapping/pushing theory. The trapped field at 77 K reaches 0.8 T, nearly 29% higher than the standard sample. The present results are very valuable for further improving the properties of YBCO bulk superconductors.

Facile fabrication of nano-composited Y–Ba–Cu–O single-grain superconductor using raw metallic oxides

Nano-composited Y–Ba–Cu–O (YBCO) single-grain superconductor has been facilely fabricated using raw metallic oxides. In this new method, a solid source pellet (SSP) of composition nano-Y2O3+BaO + CuO+1wt.%CeO2 and a liquid source pellet (LSP) of composition Yb2O3+10BaO+16CuO are employed. Because the step of precursor powder synthesis in the conventional technique can be omitted, so the whole process flow is much simplified and the experimental efficiency is advanced. Experimental results indicate that, the sample exhibits homogeneous distribution of nano-sized Y2BaCuO5 (Y-211) inclusions in microstructure, and also a Jc performance of 6.24 × 104 A/cm2 in self field at 77 K, which is about 22% higher than that observed in conventional infiltration processed sample. Consequently, this study supplies a practical method for fabricating nano-composited YBCO bulk superconductor with high performance.

Magnetic characteristics of permanent magnet guideways at low temperature and its effect on the levitation force of bulk YBaCuO superconductors

It is important to understand the influence of environmental temperature variation on high temperature superconducting (HTS) maglev performance in practice. As the on-board bulk high temperature superconductors (HTSCs) are kept in liquid nitrogen cryostats at all times, the actual temperature effects relevant to maglev performance are on the permanent magnet guideway (PMG), and these have been examined by exploring the PMG magnetic characteristics and the related interaction force with the on-board bulk HTSCs above it in this paper. The experimental temperature range was set from room temperature to 77 K. The experimental results show that the typical room temperature (RT) vertical magnetic flux density (defined as BPMG), 565 mT, of the PMG segment first increases as the temperature decreases to 138 K, before it reaches a peak of 634 mT within the temperature range from 138 K to 120 K, with a rapid growth rate to 12.2% over the RT value. And then BPMG decreases quickly to a stable value of 576 mT at 77 K. A final 1.9% enhancement ratio was obtained compared with the initial BPMG at room temperature. Furthermore, the levitation force exhibits a similar trend to the BPMG whatever the field cooling process and the zero field cooling process was conducted when the PMG temperature is reduced. Growth of 21.8% and 13.4% for the levitation force occurs for the field-cooling process and the zero-field-cooling process, respectively. The results provide basic data for environmental temperature effects on HTS maglev systems, which implies that the low temperature environment can have benefits towards enhancement of their levitation performance.

Comparisons of the microstructure and superconducting properties in Y–Ba–Cu–O single-grain superconductors grown with different liquid sources: The influence of element doping through liquid infiltration

Based on the top-seed infiltration and growth (TSIG) technique, two Y–Ba–Cu–O (YBCO) single-grain samples were successfully grown with two different kinds of liquid sources: Y2O3+10BaO+16CuO and Yb2O3+10BaO+16CuO, labeled as Y-LS and Yb-LS respectively, and systematical comparisons of their microstructure and superconducting properties were carried out. Microstructural observations indicate that the Yb-LS sample exhibits both the micro-sized Y2BaCuO5 (Y-211) particles and the nano-sized Y-211 inclusions with smaller sizes than the Y-LS sample, and the energy dispersive spectrometry (EDS) result confirms the existence of Yb element with a concentration up to 0.46wt% in Yb-LS processed sample. Measurements of superconducting properties showed that, a slightly higher levitation force (29.09N) and a slightly reduced Tc (90.3K) were observed in the Yb-LS sample, compared with the result (28.54N and 90.8K) in Y-LS sample. While for Jc property, both a higher zero-field Jc of 8.41×104A/cm2 and an obvious peak effect of 4.33×104A/cm2 at a higher field of 1.4T were observed in the Yb-LS sample, indicating the existence of stronger δl-type pinning from smaller Y-211 particles/inclusions, as well as stronger δTc-type pinning from the spatial fluctuations in matrix composition. The results prove the positive impact of the diffused Yb element on YBCO bulk superconductor and validate the element diffusion-doping route through the liquid infiltration.

A combined powder melt and infiltration growth technique for fabricating nano-composited Y−Ba−Cu−O single-grain superconductor

The top-seeded melt growth (MG) and infiltration growth (IG) techniques are the two most popular methods of fabricating single-grain Y−Ba−Cu−O (YBCO) bulk superconductors, which are also considered as two distinctly different processes. In this study, we report a combined powder melt and infiltration growth (PM-IG) technique for fabricating nano-composited YBCO single-grain superconductors using raw metallic oxides. In this new technique, a solid source pellet (SSP) of composition nano-Y2O3 + BaO + CuO + 1 wt.%CeO2 and a liquid source pellet (LSP) of composition nano-Y2O3 + 10BaO + 16CuO are employed, thus during heat treatment process the powder melt in SSP (corresponding to the final YBCO bulk) and liquid infiltration from LSP to SSP coexist. Because the process of precursor powder synthesis is avoided, the fabrication flow is much simplified and the experimental efficiency is increased significantly. Microstructural observation indicates that a large number of Y2BaCuO5 nano-inclusions (around 100 nm) are trapped in the YBa2Cu3O7−δ superconducting matrix. Measurements of levitation force and trapped field prove the superior performance of the nano-composited YBCO sample. The calculated zero-field Jc at 77 K reaches 6.98 × 104 A cm−2, nearly 23% higher than the sample fabricated by the conventional IG technique. Thus, this study supplies a practical method for fabricating nano-composited YBCO bulk superconductors with high performance.