Fazhu Ding

• Professor
• Chinese Academy of Sciences

REBa 2 Cu 3 O 7‐ x (REBCO) exhibits outstanding qualities such as a high irreversible field (7 T) and strong current‐carrying capacity (77 K, 10 ⁶ A cm ⁻² ), making it ideal for high magnetic field applications such as fusion, accelerators, and nuclear magnetic resonance. However, the degradation of in‐field critical current density ( J c ) due to...

Developing closed-loop magnets that operate in a persistent current mode (PCM) is crucial for achieving higher resolution and sensitivity in NMR and MRI devices. To the best of our knowledge, we report a novel closed-loop multi-pancake (MP) HTS magnet operated on PCM based on a novel jointless winding method with superconducting joints of REBCO coa...

REBa2Cu3O7-δ (REBCO, RE: rare earth) coated conductors (CCs) can generate a powerful magnetic field and are optimal for sustaining the reaction in fusion devices. However, the REBCO CCs will inevitably be exposed to neutron radiation during device operation. Transmutation produces gas atoms such as hydrogen will affect their properties. In this pap...

Flexible polymer/single‐wall carbon nanotube (SWCNT) composites are a vital component for wearable/portable electronics, but the development of their n‐type counterpart is laggard. Furthermore, little attention is paid to the interaction between SWCNT and polymers, especially the unconjugated polymers, as well as the conversion mechanism of conduct...

REBa2Cu3O7-x (REBCO) – основа высокотемпературных сверхпроводящих лент второго поколения – отличается прекрасными характеристиками, такими как высокое необратимое поле (7 Т) и высокая пропускная способность по току (77 К, 106 А/см2). REBCO рассматривается как потенциальный выбор для применения в условиях сильных магнитных полей (ускорители, магнитн...

Closed coils fabricated using second generation high temperature superconducting (2G-HTS) coated conductors (CCs) are promising for superconducting magnets, which operating in persistent current mode (PCM) such as magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR) systems. However, the fabrication and application of superconducti...

Although a high figure of merit (zT) over a wide range of temperatures has been shown in n‐type Zintl Mg3(Sb, Bi)2, further improvement of its near‐room‐temperature performance is still required to promote its application in next‐generation thermoelectric coolers and power generators. Here, a novel strategy of phonon spectra mismatch for enhancing...

Irradiation can precisely control defects in, and improve the superconducting properties of, REBa2Cu3O7−δ (REBCO, RE: rare earth) coated conductors (CCs). Here we report an effective approach for enhancing the in-field performance of GdBCO CCs. The critical current density (J c) of GdBCO films was significantly improved through cooperative defects...

Due to the limited thermoelectric performance of polymers and intrinsic rigidness of inorganic materials, it is difficult to obtain n-type thermoelectric materials and devices with low-cost, excellent flexibility, and high performance. In this work, we have successfully synthesized n-type flexible free-standing thermoelectric films by a low-cost so...

It is currently widely accepted that chemical bonding in a thermoelectric material should be weakened as much as possible to obtain a lower lattice thermal conductivity and thus a higher thermoelectric figure of merit, zT, but the consequent reliability issues, such as inferior structural stability and mechanical brittleness, are rarely emphasized....

To solve the problem of limited ampacity (current-carrying capacity) for pure metals, composite conductors are developed by integrating copper into macroscopic carbon nanotube (CNT) assemblies via a refined two-step organic–aqueous electrodeposition and a consequent hot compression. Due to the network-based structural confinement, efficient transpo...

Effective thermal management is quite urgent for electronics owing to their ever-growing integration degree, operation frequency and power density, and the main strategy of thermal management is to remove excess energy from electronics to outside by thermal conductive materials. Compared to the conventional thermal management materials, flexible th...

Superconducting joints are crucial for second generation high-temperature superconducting (2G HTS) closed-loop coils that work in the persistent current mode (PCM) operation. Here, we report an efficient approach for superconducting joints of YBa2Cu3O7-σ (YBCO) coated conductors (CCs). The YBCO layer is etched to and from some microchannels, which...

The rapid development of the Internet of Things increases the demand for wearable devices. Compared with traditional chemical batteries, flexible thermoelectric technology contributes a solution for solving the power supply of wearable electronics. Here, we prepared n-type Bi2Te3 and p-type Bi0.5Sb1.5Te3 flexible thermoelectric films by the magnetr...

Second-generation high-temperature superconducting (2G-HTS) tapes based on REBa2Cu3O7-x (REBCO, RE: rare earth) materials enable the energy-efficient and high-power-density delivery of electricity, thereby promoting the development of clean energy generation, conversion, transmission, and storage. To overcome the weak grain-boundary connection and...

Excellent thermoelectric performance has been realized in trace-elements-doped n-type Mg3Bi2-xSbx materials, but the structural origin for such improved performance hasn't been fully studied, inhibiting this effective approach to better performance. Here we present the characterizations and analyses of the atomic and electronic structures associate...

Achieving superconducting joinings with large current capacities is a challenge for magnetic resonance imaging applications of YBa2Cu3O7-δ (YBCO) coated conductors (CCs). Here we report a novel method to fabricate a superconducting joining between two YBCO CCs using a joining strap consisting of YBCO, Ag, a buffer, and a substrate. The YBCO layer e...

Patterned piezoelectric films as inter-digital transducer (PP-IDT) structures on diamond substrates have been attracting extensive attention due to the increased working frequency, electromechanical coupling, and quality factor of piezoelectric devices. In this study, by conceiving every single patterned piezoelectric IDT bar as the longitudinal bu...

Bismuth selenide materials (Bi2Se3) have high performance around room temperature, demonstrating potential in thermoelectric applications. Presently, most vacuum preparation techniques used to fabricate the film materials, such as magnetron sputtering and molecular beam epitaxy, usually require complex and expensive equipment. This limits the pract...

Recently, flexible thermoelectric (TE) materials and devices have attracted extensive attention due to their capability to convert heat into electricity directly and their conformal contact with arbitrarily shaped heat sources, demonstrating great promise for application in selfpowered portable/wearable low power consuming electronics. Here, we rev...

Low-grade heat harvesting by thermoelectric technology can contribute to efficient energy utilization. However, the large-scale application of thermoelectric devices is partially hindered by their unsatisfactory performance and relatively high cost. Here we prepared a cost-effective n-type Mg3Bi2-based compound with a peak zT of 1.24 at 573 K. A un...

A highly c-axis-oriented aluminum nitride (AlN) thin film with smooth and crack-free surface was fabricated by an off-normal direct current (DC) sputtering method in a pure nitrogen atmosphere, in which the rotatable substrate holder positioned in the middle of four side targets was a key approach to guarantee the grain growth with no tilt. The det...

Although YBa2Cu3O72212δ (YBCO) is one of the most promising superconducting materials for power applications, the fabrication of low-cost coated conductors with the high in-field performance remains challenging. Here, we report an efficient mixed-pinning landscape for enhancing the in-field performance of BaTiO3 (BTO)-doped YBCO films by low-energy...

The achievement of low resistance connection in ${\rm {REB_{2}C_{3}O_{7-z}}}$ (REBCO, RE=Y, Gd) coated conductors (CCs) has become one of the strategic factors for magnet applications. In this paper, we fabricated low resistivity ( ${{R_\rm {sj}=4.9\ n\Omega\cdot cm^{2}}}$ ) Ag-diffusion joints of ReBCO CCs by improving the interface connection...

The highly efficient n-type Mg3Sb2-xBix thermoelectric materials hold great promise for application in power generation as well as refrigeration. Currently, n-type Mg3Sb2-xBix compounds with high zTs can be easily reproduced on a laboratory scale with ∼10 g per batch. However, scaling up the synthesis of Mg3Sb2-xBix with uniform high thermoelectric...

N-type Mg3Sb2-x Bi x alloys have been extensively studied in recent years due to their significantly enhanced thermoelectric figure of merit (zT), thus promoting them as potential candidates for waste heat recovery and cooling applications. In this review, the effects resulting from alloying Mg3Bi2 with Mg3Sb2, including narrowed bandgap, decrease...

The trifluoroacetate metal-organic deposition (TFA-MOD) is one of the most appealing routes for the growth of high-quality YBa2Cu3O7-δ (YBCO) coated conductors (CCs) due to its advantages of low cost and high efficiency. However, the puzzle of the inhomogeneities in microstructures and superconducting properties of YBCO CCs prepared based on the TF...

The recently discovered n-type Mg3Sb2-xBix alloys with high thermoelectric performance hold great potential for applications in waste heat recovery due to their high average zT in the temperature range between 300 and 773 K. However, systematic studies of their thermal stability remain lacking and are significant for these thermoelectric materials...

The substitution of chemically similar elements in a given crystal structure is an effective way to enhance physical properties, but the understanding on such improvements is usually impeded because the substitutions are random, and the roles of the different atoms cannot be distinguished by crystallographic symmetry. Herein, we provide a detailed...

Interface control is an important method to improve the properties of Copper/Carbon Nanotubes composite. In this work, different kinds of carbide formation elements like Nb, Zr, Mo, Ti, or W is mechanically added into Cu to form composite with Carbon Nanotubes. The element doping leads carbides formed at the interface and makes the composite achiev...

Bismuth antimony telluride (Bi0.5Sb1.5Te3)-based films have excellent thermoelectric (TE) properties around room temperature. However, tremendous challenges remain for applying these materials in flexible TE devices due to their inherent brittleness and rigidity. Here we report the fabrication of flexible p-type Bi0.5Sb1.5Te3-based heterostructure...

Bi-Sb-Te-based semiconductors possess the best room-temperature thermoelectric performance, but, which are restricted for application in wearable field due to its inherent brittleness, rigidity, and non-scalable manufacturing techniques. Therefore, how to obtain thermoelectric materials with excellent thermoelectric properties and flexibility throu...

The YBa $_2$ Cu $_3$ O $_{7-x}$ (YBCO) coated conductor (CC) is one of the most promising wires because of their high critical current ( $I_c$ ) and low dependency of the $I_c$ on the external magnetic field. For superconducting applications, a large number of joints are required to join relatively short YBCO CCs. In this paper, we study the...

This paper describes an innovative electro-acoustic coupling structure with a Patterned Piezoelectric film as Inter-Digital Transducer (PP-IDT) on the diamond substrate for Surface Acoustic Wave (SAW) devices of better quality factor and frequency resolution. Theoretical analysis and Finite Element Method (FEM) are employed to investigate the depen...

YBCO films doped with different contents of gadolinium (Gd) were prepared by the low-fluorine (low-F) trifluoroacetate metal-organic deposition (MOD) method. The effects of flow rate and holding time of the firing (crystallization) stage on the superconducting properties of YxGd1–xBa2Cu3O7–δ (YGdBCO) films were investigated. The phase formation and...

It is of great significance to understand the interactions between nanoparticles and polymers since they guide the development of tremendous applications in, for example, optoelectronic devices, biomedicine, and enhanced oil extraction. However, few studies have probed into this fundamental science as it relates to the emerging amphiphilic Janus na...

The YBa 2 Cu 3 O 7−x coated conductor (YBCO CC) is one of the most promising superconducting materials for magnet applications because of its high critical current (I c ) and low dependency of the I c on the external magnetic field. For magnet applications, plenty of joints are required to meet the connection of relatively short YBCO CC tapes. The...

Transition-metal nitrides have increasingly attracted interest for use as electrocatalysts in water splitting due to their superior catalytic activity and stability. However, the development of a general and simple strategy to synthesize metal nitrides remains challenging. Here we report a facile strategy for the synthesis of various porous monomet...

A universal synthesis strategy to make metal nitride electrocatalysts for hydrogen evolution reaction Transition-metal nitrides have increasingly attracted interest for use as electrocatalysts in water splitting. This work develops a universal and facile approach for the direct synthesis of porous monometallic and bimetallic nitride nanoparticles o...

The heating temperature of the silicon carbide sublimation growth crucible is changed by adjusting the output power of the medium frequency induction coil, and the sintering experiments were carried out using NaCl and Al 2 O 3 to observe the morphological changes after sintered under different output power, the corresponding temperature was determi...

The preparation of YBa2Cu3O7−x (YBCO) film by low fluorine metal-organic deposition methodology has been extensively studied recently for its high efficiency and low cost. However, the relationship between the heating rate during pyrolysis and the fluorine content of precursor is still unclear and hence no universal thermal process has been widely...

Despite the composition close to glassy forming alloys, face centered cubic (FCC) Co81.8Si9.1B9.1, designed based on Co9B atomic cluster (polyhedral), are synthesized as singlephase ribbons successfully. These ribbons, with grain sizes of ca. 92 nm, show supreme ductility and strong orientation along (111), which couples with shape anisotropy leadi...

Monolayer graphene with high quality was synthesized by pyrolysis of 6H-silicon carbide single crystal in a medium frequency induction heating furnace. The obtained graphene was systematically studied via Raman spectroscopy, atomic force microscopy (AFM), and high-resolution transmission electron microscopy (HRTEM). The characterized results showed...

The demand for coated conductors with high cost performance has triggered the search for effective artificial pinning centers by the low cost and high-scalability route. In this work, YBa2Cu3O7−x (YBCO) nanocomposite films with BaMnO3 nanosized particles induced by manganese (Mn) addition were prepared by low-fluorine metal-organic deposition. A st...

Introducing nanoscale heterostructure interfaces into materials matrix is an effective strategy to optimize the thermoelectric performance by energy-dependent carrier filtering effect. In this study, highly (00l)-oriented Bi2Te3/Te heterostructure thin films have been fabricated on single-crystal MgO substrates using a facile magnetron co-sputterin...

The second-generation high-temperature superconductor (2G HTS) is a good candidate for high field magnet due to its high critical temperature Tc, high critical current density Jc, and high irreversibility field Hirr. This paper presents the design and development of a 4.08 T (46 K) coil made of homemade 2G HTS. In order to meet the design requireme...

By using the atomic cluster model, face centered cubic (FCC) Co81.8Si9.1B9.1 compound is designed and synthesized as ductile single-phase ribbons successfully. These ribbons show strong orientation along (111) and high magnetocrystalline anisotropy with a coercivity of 430 Oe and squareness of 0.82 at room temperature. The large spin–orbit coupling...

Bi2Te3 thin films were fabricated on the (00l)-oriented MgO substrates by the magnetron co-sputtering method. The films microstructure of highly preferred orientation along the c-axis had been obtained through the inducing of single crystal MgO substrates. And some abundant Te was introduced into the Bi2Te3 films through sputtering tellurium target...

The CaTiO3 (CTO) films were epitaxially grown on (00l)-oriented LaAlO3 (LAO) single-crystal substrates by sol-gel method. The final CTO film shows a good biaxial texture, especially with a very small full width at half maximum value of ϕ- scans of about 0.32°. The epitaxial relationship between CTO film and LAO substrate are CTO [110] // LAO [100]...

BaTiO3 (BTO)-doped YBa2Cu3O7-δ (YBCO) films were prepared by the metal-organic deposition method using a precursor solution with titanium ion. These YBCO films were deposited on (00l)-oriented LaAlO3 single-crystal substrates using an automated dip coater. The thickness dependence of critical current density (JC) in the BTO-doped YBCO films was inv...

Bismuth telluride films were prepared on the quartz glass by magnetron sputtering at various temperatures. Co-sputtering method with the alloying Bi2Te3 and Te targets was adopted to adjust the content of Te. The influence of Te content and deposition temperature on microstructure and thermoelectric performance was investigated systematically. Irre...

In YBa2Cu3O7-x (YBCO) film there exists "thickness effect" : the critical current density of YBCO film drops precipitously as the coating thickness increases, especially in the case that the thickness of YBCO film exceeds 1 μm. In this paper, we introduce very thin layers of CeO2 into YBCO layers and successfully fabricate the structure of YBCO/YBC...

YBa2Cu3O 7−δ (YBCO) films with BaTiO3 (BTO) nanostructures were prepared by using the precursor solutions with different cationic molar ratios of Y:Ba:Cu = 1.0:1.6–2.0:3.0 in the TFA-MOD process. These YBCO films were deposited on (00 l)-oriented LaAlO3 single-crystal substrates using a spin coater. The high superconducting critical current density...

YBa2Cu3O7−δ (YBCO) films with BaTiO3 (BTO) nanostructures were prepared by the low-fluorine trifluoroacetate-metal-organic deposition process using the precursor solution with the molar ratio of Y:Ba:Cu = 1.0:1.8:3.0. The high superconducting critical current density (JC) (77 K, self-filed) of 10 MA/cm2 for YBCO films was obtained. This result aris...

YBa2Cu3O7−x (YBCO) films with co-doping of BaTiO3 (BTO) and Y2O3 nanostructures were successfully fabricated on LaAlO3 (LAO) substrate by metal organic deposition using trifluoroacetates (TFA-MOD). The focus of this study was to optimize the process conditions during the firing heat treatment of high critical current density (J C)-co-doped YBCO fil...

Aluminum-doped zinc oxide (ZnO:Al) films were deposited by direct current magnetron sputtering in incorporating hydrogen in sputtering gas at room temperature. The influences of hydrogen content in sputtering gas on the structural, optical, and electrical properties of ZnO:Al films were systematically investigated. It is found that hydrogen incorpo...

YBCO thin films with BaTiO3 nanocolumns were fabricated on (0 0 l) oriented LaAlO3 substrates by metal-organic deposition (MOD). High critical current density (J(c)) up to 10 MA/cm(2) has been observed on these self-assembled BaTiO3 nanocolumns doped YBCO films at 77K and self-field. These BaTiO3 nanocolumns had no preferential orientation and were...

Sulfonated magnetic microspheres (PSt-DVB-SNa MPs) have been successfully prepared as adsorbents via an aqueous suspension polymerization of styrene-divinylbenzene and a sulfonation reaction successively. The resulting adsorbents were confirmed by means of Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), transmission electron mi...

In this paper, sodium citrate was adopted as a complexing agent and ammonia merely served as pH adjustor to investigate the growth mechanism of CdS film. The growth rate, structural properties, surface morphology, microstructure, and optical properties of CdS films were studied by profilometer, X-ray diffractometer (XRD), scanning electron microsco...

YBa2Cu3O7-x (YBCO) coated conductors, the second generation (2G) high temperature superconducting (HTS) wires, are widely applied in the field of strong electricity, mainly because of the high irreversible field and the intrinsic carrier capability (77 K). As the second generation HTS wires have been developed to be the practical superconducting ma...

The relationship between microstructure and energy band gap of CdS films prepared by chemical bath deposition was studied. The growth rate, structural properties, optical properties, surface morphologies and film composition of CdS films prepared at different deposition temperatures were investigated by profilometer, X-ray diffractometer(XRD), tran...

Chemical badi deposition was one of the most important methods to prepare CdS films. The properties of CdS films could be substantially influenced by the solution agitation methods. CdS films were prepared by chemical bath deposition; stirring, without solution agitation, ultrasonication and vibration, respectively. The growth rate, structural and...

In this article, the growth process of chemical bath deposited CdS films was systematically investigated. The structural, optical, and morphological properties were investigated by X-ray diffraction (XRD), transmission electron microscope (TEM), UV–Vis spectrophotometer, scanning electron microscope (SEM), respectively. CdS nanocubes with size of l...

Enhancing the critical-current density of YBCO films is essential to gain a deeper understanding of the vortex pinning mechanisms and enable commercial applications of high-temperature superconductivity. Combined BaCeO3 and Y2O3 nanoparticles have been achieved to be co-doped in YBa2Cu3O7-x (YBCO) films by metalorganic deposition using trifluoroace...

YBa2Cu3O7−x (YBCO) films with embedded BaZrO3 and BaTiO3 nanoparticles were fabricated by metalorganic deposition using trifluoroacetates (TFA-MOD). Both X-ray diffraction and transmission electron microscopy revealed that these BaZrO3 and BaTiO3 nanoparticles had random orientations and were distributed stochastically in the YBCO matrix. The uniqu...

PbS quantum dots (QDs) have enormous potential for applications ranging from tunable infrared lasers to solar cells due to their efficient emission over a large spectral range in the infrared. Especially, multiple exciton generation has been observed in PbS QDs, which makes PbS QDs have great potential for high-efficiency solar cells. However, thes...

Hydrogen isotope permeation barriers (HIPB) have great potential applications in the fields of hydrogen energy and thermonuclear fusion energy. Here, we report the stability of Y2O3 HIPB in gaseous hydrogen at high temperatures including the structures, mechanical properties and electrical properties. With increasing hydrogen treatment time at 700...

Owing to the adaptability to large scale processing, excellent composition control and film uniformity, the metal-organic chemical vapor deposition (MOCVD) technique is a promising process for high-temperature superconductor YBa2Cu3O7-delta(YBCO) preparation. In this technique, the evaporation characteristics and thermostability of adopted precurso...

The metal-organic chemical vapor deposition (MOCVD) technique is a promising process for high-temperature superconductor YBa2Cu3O7−δ(YBCO) preparation. In this technique, it is a challenge to obtain barium precursors with high volatility. In addition, the purity, evaporation characteristics and thermostability of adopted precursors in the whole pro...

The metal-organic chemical vapor deposition (MOCVD) technique is a promising process for high temperature superconductor YBa2Cu3O7-d (YBCO) preparation. In this technique, the purity, evaporation characteristics and thermostability of adopted precursors will decide the quality and reproducible results of YBCO film. In the present report, tris(2,2,6...

A combined BaZrO3 (BZO) and Y2O3 nanoparticles has been achieved in YBa2Cu3O7−x (YBCO) films by metalorganic deposition using trifluoroacetates (TFA-MOD). The formation of integrated nanoparticles increases the critical current density (Jc) of Y2O3/BZO doped-YBCO films while keeping the critical transition temperature (Tc) close to that in the pure...

The surface condition of substrate tape is an important factor to obtain epitaxial buffer layer on biaxially textured Ni tape for YBa 2Cu 3O 7-x coated conductors. We prepare ceria films on Ni single crystal, biaxially textured Ni tape and sulfured Ni substrates by direct current magnetron sputtering. The results show that the ceria films prepared...

Epitaxial YBa2Cu3O7−x /BaZrO3 films were prepared by complex metal–organic solutions including Y, Ba and Cu anhydrous trifluoroacetate precursors and Zr acetylacetonate precursors. The influence of the amount of BaZrO3 (BZO) on the structure and properties of YBa2Cu3O7−x (YBCO) films was systematically investigated. The YBCO films having 7 mol % BZ...

The surface condition of substrate tape is an important factor to obtain epitaxial buffer layer on biaxially textured Ni tape for YBa2Cu3O7-x coated conductors. We prepare ceria films on Ni single crystal, biaxially textured Ni tape and sulfured Ni substrates by direct current magnetron sputtering. The results show that the ceria films prepared on...

The YBCO films were prepared on LAO single crystal by TFA-MOD process. The structure and properties of YBCO films were investigated through changing the Y123 stoichiometry. It is found that higher J C values in self-filed of YBCO films are achieved by using the starting solution with the Ba:Y ratio of 1.5:1. X-ray diffraction analysis revealed that...

We fabricated YBa2Cu3O7−x (YBCO) films on LaAlO3 (LAO) substrates using metal organic deposition of precursor solutions containing metal trifluoroacetates (TFA-MOD). The effect of water vapor pressure on the microstructure, degree of texture, and critical current of prepared YBCO films was evaluated. The firing process was performed in the water va...

Using a novel DC magnetron sputtering system, high quality YBa2Cu3O7−δ (YBCO) thin films were deposited on both sides of twelve pieces of 3-inch LaAlO3(00l) single crystal substrates in one batch. This sputtering system has a rotatable disc sample holder with the LaAlO3 substrates being positioned in the middle of upper and lower YBCO targets. Thes...

This paper systematically investigates the intermediate phases of YBa2Cu3O7−x (YBCO) film prepared by metalorganic deposition method using trifluoroacetates (TFA-MOD). According to x-ray diffraction and Raman analyses, the precursor film decomposed in a mixture of BaF2, Y2O3 and CuO after the pyrolysis process. Then these intermediate phases conver...

Large-area YBa2Cu3O7−x (YBCO) films had been successfully fabricated on LaAlO3 (LAO) substrate by metalorganic deposition using trifluoroacetates (TFA-MOD) and the effect of air humidity on the structure and properties of YBCO films was systematically investigated. The precursor coating process was performed in the air humidity range of 70–40%. Acc...