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The synergistic effects of double doping with a positive mismatch perovskite (Ba2YNbO6) and a negative mismatch perovskite (LaAlO3) on the brittle ceramic YBa2Cu3O7-x (YBCO) superconducting films w...

This study is to fabricate a composite substrate (Ni7W/Ni12W/Ni7W) with weak magnetization, strong reinforcement, and improved cube texture via Rolling Assisted Biaxially Textured Substrates (RABiTS) route. The formation of cube texture with reduction in twin boundaries due to recrystallization annealing was investigated thoroughly. The optimized recrystallization annealing process revealed 97.4% of cube texture and 83.9% of small angle grain boundaries at an angle of (

In this work the formation of strong recrystallization cube texture in heavily rolled Ni–9.3 at % W has been studied. During the cold rolling (also known as recovery-rolling) process the deformation texture of Ni–9.3 at % W alloy (further notated as Ni9W) transforms to Copper-type rolling texture, and after annealing, a sharp cube texture is generated. It is remarkably strong recrystallization cube texture, as high as 93 vol %, in metallic materials with low stacking fault energy. The formation mechanism of the cube texture is adopted for the rapid recovery of cube nuclei at the early stage of recrystallization as well as fast migration rate of high angle boundaries between cube grains and deformed microstructure at high temperature. Considering the cold rolling texture of Ni9W, oriented nucleation seems to play more important role in the cube texture formation process. In this article, the relationship between the deformation texture and recrystallization cube texture is discussed.

Using an environmentally friendly acid-alcohol system solution for electrochemical polishing of 3D printed titanium alloy, a typical U-I polarization curve was obtained, and explained the mechanism of electrochemical polishing. In this paper, the influence of electrochemical polishing factors (electrolyte temperature, polishing distance, and polishing time) on the surface roughness of Ti-6Al-4V (TC4) was studied, and optimized the process parameters to obtain a surface roughness of 0.3 μm (1 mm × 1 mm). Electrochemical polishing can reach the level of mechanical grinding and polishing, meeting the requirements for subsequent assembly and use.

The preparation of 80 nm, 140 nm, and 200 nm La 2 Zr 2 O 7 (LZO) multilayers on biaxially textured Ni-5 at% W (Ni5W) substrates using chemical solution deposition (CSD) was studied. The performance of multilayers was studied by means of X-Ray Diffraction (XRD), Electron Back Scattering Diffraction (EBSD), and Auger Electron Spectrometry (AES). The as-grown buffer layers exhibit sharp texture with texture components (0°−10°) about 96.7%, 98.9%, and 98.8%, respectively. The full-width at half maximum (FWHM) values of the ω-scans decreases with the number of layers, close to that of Ni5W substrates. The films exhibit dense, smooth, crack-free surface with a roughness Ra 3–5 nm, and sufficient barrier function against metal ionic diffusion from Ni5W substrates into buffer layers. The performance of LZO multilayers was confirmed by YBa 2 Cu 3 O 7−x (YBCO) films deposited by CSD technology.

Electron Backscattered Scattering Detection (EBSD) was used to characterize the texture of La 2 Zr 2 O 7 (LZO) buffer layers prepared by chemical solution deposition on Ni-5at.% W(Ni5W) biaxially textured substrates. We investigated the texture forming process of LZO films with different cation concentrations of the precursor solution. In this paper, the texture evolution mainly depends on the film thickness and on the grain growth. With low cation concentrations in the precursor solution, the discontinuous LZO grains do not completely cover the Ni5W substrates and exhibit large lattice misorientation with respect to Ni5W (defined as cube orientation). A 45° rotation orientation is found to coexist with the cube orientation and is mainly transformed by the cube orientation with increasing thickness. The interface energy minimization may play a dominant role in texture transformation.

In this work the ability of pure surfactant Sodium Dodecyl Sulfate (SDS), Cetyltrimethyl Ammonium Bromide (CTAB) and their mixed surfactants for graphene dispersion in aqueous solution was investigated. The uniform and stable dispersion solution was obtained for graphene with the mixtures of SDS and CTAB at lower concentration as compared to the pure one. The SDS-based surfactants exhibited better dispersion as compared to CTAB-based surfactants due to smaller-sized graphene as was investigated via Zeta potential measurements. Zeta potential was utilized to characterize the colloidal stability of surface charges within the mixtures. The mixed surfactants utilized in the present study showed a better ability to disperse graphene and its derivatives and hence are well suited for practical applications.

A thorough study of the growth and characterization of La 2 Zr 2 O 7 (LZO) buffer layers prepared by chemical solution deposition on Ni–5 at% W biaxially textured substrates is presented. The main focus is to understand the processes of film growth, texture evolution, and lattice misorientation during heat treatment to obtain biaxially textured LZO buffer layers with a high degree of texture. We report a systematic investigation of LZO film growth with varying cation concentrations and processing temperatures. 45° rotated misorientation crystallization is found to coexist with the cube-on-cube orientation and maybe partially formed by the transformation of the cube-on-cube orientation with increasing annealing temperature. The texture component improves with increasing surface crystallinity. These epitaxially grown LZO buffer layers have a dense and smooth structure and a texture component of 98–99%.

Ni-5 at.%W (Ni5W) tapes with a strong cube texture were fabricated using the RABiTS technique and by starting from cylindrical shaped ingots. In contrast to a conventional cuboid-shaped ingot, a cylinder shaped ingot has no anisotropy along the axial direction and the resulting tape will therefore, during heavy cold rolling, be characterized by a lower concentration of stress along the edges of the ingot. It can reduce fabrication costs and increase process efficiency. The fraction of cube texture on the surface of the finally recrystallized tapes was investigated using the EBSD technique. It was observed that the fraction of cube texture within 10° from the ideal {001}〈100〉 orientation was ~98% and the fraction of LAGBs was ~90%. The as-obtained tapes have a strong cube texture also very close to the edge of the tape and they would therefore increase the fraction of applicable material while simplifying the heavy rolling process. Accordingly, it suggests that this fabrication method is a good choice to most small scale research laboratories for achieving long length Ni5W tapes for coated conductors with an easy way and a higher fraction of applicable material.

The high critical current density of YBCO-coated conductors prepared by rolling assisted biaxially textured substrate technic is mostly based on the high quality cube-textured substrates. In this paper, the effect of initial grain size of ingot on the microstructure and texture evolutions during cold rolling has been investigated in high alloyed Ni8W ingots, which can affect the cube texture formation in Ni8W alloy substrates subsequently. Finally, high quality cube texture had been obtained in Ni8W alloy substrate with fine initial grain size prepared by advanced SPS technology.

A modified YSZ thermal barrier coating (TBC) was prepared by simultaneously depositing two components, NiCrAlY and YSZ, on nicked-based superalloy DZ125 via atmospheric plasma spraying. In this study, the sodium salt was deposited on substrate surface. After being heated at 950°C for 50min, the specimens were cooled to ambient temperature within 10 min. The specimens were recoated after each 10 cycles. Subsequently, the corrosion products were analyzed via X-Ray diffraction and SEM. The results indicated that deterioration of YSZ coating mainly resulted from generation of chemical interaction. Conversely, abnormal growth of TGO and enrichment of molten salt around segmentation crack were not observed in the modified YSZ thermal barrier coating. Moreover, the modified YSZ-TBC exhibited higher thermal resistance than traditional YSZ-TBC in the thermal cycling testing.

We investigate the effect of silver addition to polycrystalline Sm-1111 superconductor. We show that Ag improves the phase homogeneity of the samples drastically reducing the weight of the low temperature, hence, leading to less fluorinated phases. The intragranular critical current density is enhanced by adding a small amount of Ag in all pinning regimes but a higher content of Ag leads to a decrease of this quantity. A tentative explanation for this dependence is proposed.

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.

Cube texture formation of Cu-33 at.%Ni alloy substartes and CeO2buffer layer prepared by chemical solution deposition on the textured substrate were investigated by electron back scattered diffraction (EBSD) and XRD technics systematically. The results shown that a strong cube textured Cu-33at.%Ni alloy substrate with the cube texture fraction of 99.8 % (< 10°) was obtained after annealing at 1000°C for 1 h. The full width half maximum (FWHM) values for the X-ray (111) phi-scan and (002) omega-scan in this substrate were 7.31° and 5.51°, respectively. Furthermore, the cube texture fraction of epitaxially grown CeO2buffer layer was 95 % (< 10°), and the FWHM values of phi-scan and omega-scan being 6.98° and 5.92°, respectively.

Ni8W alloy ingots were prepared by SPS technic, followed by homogenizing, cold rolling and recrystallization annealing. The influence of ball milling on cold rolling and cube texture formation of Ni8W alloy substrates was investigated during the course of preparation. Finally, high quality cube-textured Ni8W alloy substrates were successfully obtained using this powder metallurgy process, and characterized by electron backscatter diffraction technic. It indicated that the cube texture fraction was as high as 90% (o) when it annealed at 1350°C for 2 h.

A modified YSZ thermal barrier coating (TBC) was prepared by simultaneously depositing two components, NiCrAlY and YSZ, on nicked-based superalloy DZ125 via atmospheric plasma spraying. In this study, the sodium salt was deposited on substrate surface at the deposition rate of 3 mg/cm-2. After being heated at 950 °C for 50min, the specimens were cooled to ambient temperature within 10 min. The specimens were recoated after each 10 cycles. Subsequently, the corrosion products were analyzed via X-Ray diffraction and SEM. The results indicated that deterioration of traditional YSZ coating mainly resulted from the fluxing of thermal grown oxides (TGO). Conversely, abnormal growth of TGO and enrichment of molten salt around segmentation crack were not observed in the modified YSZ thermal barrier coating. Moreover, the modified YSZ-TBC exhibited higher thermal resistance than traditional YSZ-TBC in the thermal cycling testing.

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.

The biomimetic method of achieving dense platelike grain growth of the high temperature superconducting ceramic YBa2Cu3O7 (YBCO) has been studied. By using various organic matrices (dextran and chitosan) having different molecular structures, the final size and arrangement of the platelike YBCO grains exhibit significant differences, possible reasons for which are discussed. The different organic matrices used also indirectly affect the superconducting properties of the YBCO formed. By elucidating the role of the organic matrix in the biomimetic synthesis process in this way, the whole process could be controlled more precisely, leading to structural and electrical properties of the final product more desireable for specific applications.

The YBCO films with doped YSZ nanoparticles have been prepared successfully by metal organic doepositon method using trifluoroacetates (TFA-MOD) through dissolving Zr organic salt into the YBCO precursor solution. The doped films have well in-plane and out-plane textures detected by both XRD Φ-scan and ω-scan. The YSZ nanoparticles with the size of about 5 ~ 15 nm were observed on the surface of the YBCO films using both FE-SEM and TEM. By comparing the superconducting properties, it was found that the doped YBCO films had lower Tc than that of undoped YBCO films. However, as increasing the applied magnetic field, Jc of the doped YBCO films were much better than that of undoped one. The Jc was as higher as 2.5 times than that of undoped YBCO film at 77 K and 1 T applied field.

The co-doped MgB2 bulk samples have been synthesized using an in situ reaction processing. The additives is 8 wt.% SiC nano powders and 10 wt.% [(CH2CHCOO)2Zn]n poly zinc acrylate complexes (PZA). A systematic study was performed on samples doped with SiC or PZA and samples co-doped with both of them. The effects of doping and co-doping on phase formation, microstructure, and the variation of lattice parameters were studied. The amount of substituted carbon, the critical temperature (Tc) and the critical current density (Jc) were determined. The calculated lattice parameters show the decrease of the a-axis, while no obvious change was detected for c-axis parameter in co-doped samples. This indicates that the carbon was substituted by boron in MgB2. The amount of substituted carbon for the co-doped sample shows an enhancement compared to that of the both single doped samples. The co-doped samples perform the highest Jc values, which reaches 3.3 × 104 A/cm2 at 5 K and 7 T. It is shown that co-doping with SiC and organic compound is an effective way to further improve the superconducting properties of MgB2.

In this work, highly cube textured Ni–7at.%W (Ni7W) substrate was fabricated from the ingots synthesized by Spark Plasma Sintering (SPS) technique. Both the La 2 Zr 2 O 7 (LZO) buffer layer and the YBCO superconducting layer were coated using chemical solution deposition (CSD) and pulsed laser deposition (PLD) layer by layer. The full-width-at-half-maximum (FWHM) values of the (1 1 1) phi-scan and the (2 0 0) ω -scan in rolling direction of the Ni7W substrate were 6.30° and 5.08°, respectively. The EBSD analyses indicated that the percentage of the cube texture component on the surface of the as-obtained Ni7W substrate was 99.4% within a tolerance angle of less than 10°. Highly epitaxial growth of homogenous crack-free LZO film was obtained cube-on-cube relative to the Ni7W substrate, with FWHM values of (2 2 2) phi-scan and (4 0 0) ω -scan of 7.57° and 5.73°, respectively. The critical temperature of the YBCO layer prepared on LZO/Ni7 W substrate is about 90.5 K, while the critical current density is 1.25 MA cm −2 (77 K, sf).

It is difficult to obtain a sharp cube texture in the Ni-9.3at.% W substrate used for coated conductors due to its low stacking fault energy. In this paper, the traditional cold rolling procedure was optimized by introducing an intermediate recovery annealing. The deformation texture has been improved after three recovery annealing cycles at 500$^{\circ}{\rm C}$ for 2 h during the cold rolling process. After optimized recrystallization annealing, a Ni-9.3at.% substrate with a cube texture content of 87.7% $( has been obtained. The effect of the intermediate annealing on cube texture formation is attributed to the improved deformation texture and to the enhanced pre-existing cube oriented structure in the deformed matrix.

采用硝酸盐为前驱盐制备涂层导体结构中的La 2 Zr 2 O 7 (LZO)过渡层. 实验通过对前驱盐粉体热分解行为的分析, 以及前驱盐溶液在铝酸镧(LAO)单晶和Ni5W合金基底上外延生长LZO膜层工艺的比较研究, 经优化获得了采用硝酸盐为前驱盐, 适用于Ni5W合金基底的低温两步热处理结合高温快速热处理制备LZO的工艺路线. 研究发现, 硝酸盐热分解过程及中间产物分解对外延织构的生成起着重要的作用. 取向分析显示LZO膜层(222)phi扫描和(400)ω扫描的半高宽分别为8.5°和8.1°, 这表明LZO膜层形成了较好的立方织构. SEM分析显示该工艺制备的膜层均匀致密, 没有裂纹和孔洞. 以上研究表明硝酸盐法可以应用于LZO过渡层的制备.

Series of rod samples of Zr55Al10Ni5Cu30 alloy were prepared by magnetic suspend melting and copper mold suction casting method using 99.9wt% high purity zirconium and 99.4wt% low purity sponge zirconium respectively, the effect of purity of zirconium material on mechanical properties and microstructure of Zr-based bulk metallic glass were investigated. The result shows that high purity material alloy could enhance the thermal stability and glass forming ability of Zr-based bulk amorphous alloy, compression fracture surface analysis indicate that the vein patterns density increase with the material elements purity increase, the average compressive fracture strength is increased to 8.52% than that of low purity samples.

The improvement of mechanical and magnetic properties of textured NiW alloy tapes are considered as a main challenge for RABiTS substrates in coated conductors. The present paper summaries the successful development of several textured NiW substrate tapes with high W contents as well as advanced NiW composite substrates with high strength and reduced magnetization. The fabrication processes of these tapes and their characterizations are presented in detail. The results on the texture quality and mechanical properties as well as on the magnetic behaviors of these tapes are promising in view of the future application in coated conductor and constitute an alternative to the well known Ni5W RABiTS substrates.

In this paper, we presented the results of YBCO films deposited epitaxially on both SrTiO3 single crystal and textured Ag substrates by a TFA-MOD method. The growing conditions and forming mechanisms of the YBCO films on these two kinds of substrates was investigated systematically. It was found that the precursor film coated on Ag substrate took less time to completely decompose to an amorphous precursor film during the first stage of the calcination than that on SrTiO3 substrate. Moreover, the higher temperature was needed to obtain pure YBCO phase on Ag substrate during the second annealing stage. A possible growing mechanism for this difference was described. A transport jc value of 1.5 x 104 A/cm2 (at 77 K) was obtained for the YBCO film deposited on Ag substrate, while the film on SrTiO3 substrate exhibited an a Tc onset of 92 K and a high jc value of 2.3 MA/cm2 at 77 K in self-field was measured.

In-situ MgB2/Fe tapes were fabricated by the powder in tube (PIT) technology using Mg and B powders. The tapes were sintered by both an advanced spark plasma sintering (SPS) and a conventional vacuum furnace, respectively. The effects of these two sintering routes on the properties of the MgB2 tapes were investigated by the analysis of XRD, SEM and the magnetic Jc measurements. It was shown that at 10K, 0T, the magnetic Jc value of the tape sintered using SPS machine at 800°C for 15min under 30MPa were close to 106A/cm2, which was higher than that of the tapes annealed at 700°C for 2h under pressureless vacuum condition. It was found that the density and the homogeneity of the MgB2 core were strongly improved using SPS sintering process, which explained why the MgB2 tapes sintered by SPS method have a higher Jc value. Further enhancement of Jc in the tapes is expected for the understanding of the SPS sintering mechanism.

CeO2 has been considered as one of the most lattice compatible and chemically stable materials for YBa2Cu3O7-x coated conductors. In this paper, we presented the epitaxial growth of CeO2 thin film on both YSZ single crystal and cube textured Ni5W substrates by MOD method. Homogenous, crack-free and dense CeO2 thin films on both substrates with sharp biaxially cube texture were fabricated by post-annealing the precursor films at 1000-1150°C. For the CeO2 film on the textured Ni5W substrate, the FWHM values of (111) Phi-scan and (002) rocking curve were around 6°and 7°, respectively, the surface roughness was less than 2 nm over an area of 1μm×1μm observed by AFM. It was found that the CeO2 thin film improved both the in-plane orientation and surface roughness of the Ni5W substrate, indicating that the as deposited CeO2 films were suitable for the further growth of YBCO superconductor layer.

It is well know that Ni-5at.% W(Ni5W) and Ni-9.3at.% W(Ni9W) alloy substrates are two kinds of promising materials to be employed in coated conductors. The Ni5W substrate is very easy to produce cube texture, while the Ni9W alloy has a lower magnetic property and higher strength. However, the pure cube texture are not capable to be obtained in Ni9W alloy. In this work, the preparation and texture development in both Ni5W and Ni9W alloy substrates have been reported. Highly biaxial textured Ni5W substrate was fabricated by cold rolling, followed by three different annealing routes. The texture analysis indicated that a sharp cube texture was formed after annealing at a wide temperature range of 800-1100°C in as rolled Ni5W substrate. The high quality of cube orientation was obtained after a two step annealing (TSA) with farthing twin boundaries analyzed by EBSD. Furthermore, in order to obtain a pure cube texture in Ni9W alloy substrate, a typical rolling process was performed and the deformation texture was optimized in these substrates. The designed deformation texture components were obtained in Ni9W alloy when pre-heating the ingot at 250 °C before performing a cold rolling, which shows a possibility to form cube texture in Ni9W alloy substrate after annealing.

YBa2Cu3O7-δ (YBCO) films were deposited on (100), (110) and (111) oriented silver single crystals and {100}, {110} , {110}+{110}， {110} and {012} textured Ag substrates using pulsed laser deposition. The relationship between the epitaxial growth YBCO film and silver substrate has been determined. It is shown that among polycrystalline Ag substrates, {110} textured tape is suitable for the deposition of YBCO thin films having strong texture.

The aim of our work is to produce biaxially aligned HTS conductors by epitaxial growth on textured Ag. This paper will focus on the preparation of long length textured Ag ribbons. After cold rolling and annealing in vacuum at 800/spl deg/C, different {110} directions appear in the recrystallized pure Ag ribbons. The {110} texture is obtained after cold rolling by adding a 500/spl deg/C step before the annealing at 800/spl deg/C. If the Ag ingots are annealed at 600/spl deg/C in vacuum before the cold rolling, the 800/spl deg/C annealing leads to a sharp {110} texture. The quality of the texture is studied by X-ray and electronic diffraction. Three X-ray pole figures are used to calculate the ODF function, a SEM is used to obtain orientation maps from EBDP. The surface roughness is studied by AFM. We have produced lengths of 25 cm with a sharp {110} texture (FWHM=7/spl deg/ ODF peak). The characteristics of the two {110} and {110} orientation are presented in detail. It is shown that those {110} ribbons are suitable for epitaxial growth of superconducting cuprates. The Ag textured ribbons are used as substrates for different superconducting systems such as Tl-1223 and Y123.

The YBCO films were directly deposited on the {1 1 0} 〈0 1 1〉 textured Ag substrates by ultrasonic spray pyrolysis method. The observed white points in YBCO film by one-step deposition at 900 °C consisted in high content of Ag on the surface of this film, which was due to the evaporation and diffusion of Ag atoms at high deposition temperature. While the performance of YBCO films was significantly enhanced using two-step deposition route. A 15 cm length of coated YBCO film on {1 1 0} 〈0 1 1〉 textured Ag tape was prepared by this two-step deposition method, which exhibited a transport J c value of more than 10 4 A/cm 2 (at 77 K).

High performance long-length coated conductors fabricated using various techniques have attracted a lot of interest recently. In this work, a reel-to-reel design for depositing double-sided coatings on long-length flexible metallic tapes via a chemical solution method is proposed and realized. The major achievement of the design is to combine the dip coating and drying processes in order to overcome the technical difficulties of dealing with the wet films on both sides of the tape. We report the successful application of the design to fabricate a one-meter-long double side coated CeO2/Ni-5at%W template. The CeO2 films on both sides exhibit a dense, crack-free morphology, and a high fraction of cube texture on the surface. Homogeneity studies on global texture over the length also reveal that the average full width at half maximum values of the in-plane and out-of-plane orientation on the CeO2 layer are 7.2 ° and 5.8° with standard deviation of 0.26° and 0.34°, respectively, being indicative of the high quality epitaxial growth of the films prepared in the continuous manner. An all chemical solution derived YBCOLow-TFA/Ce0.9La0.1O2 /Gd2Zr2O7/CeO2 structure is obtained on a short sample, demonstrating the possibility of producing long-length texture templates for coated conductors by this low cost deposition route.

We present a thorough study of the nucleation and growth processes of the solution-based YBa2Cu3O7?Ba2YTaO6 (YBCO?BYTO) system, carried out with a view to controlling the characteristics of the BYTO phase to meet the requirements for specific power applications. Scanning transmission electron microscopy and x-ray diffraction have been used to characterize the BYTO nucleation and phase evolution during the YBCO?BYTO conversion. At high BYTO loads (>10?mol%), the nanoparticles tend to aggregate, resulting in much less efficiency for generating nanostrained areas in the YBCO matrix, and enhancement of the vortex pinning. Our experiments show that by modifying the nucleation kinetics and thermodynamics of the BYTO, the nucleation mode (homogeneous versus heterogeneous), the particle size and the particle orientation can be controlled. We demonstrate that YBCO?BYTO nanocomposites with high concentration of nanoparticles can be prepared in such a way as to obtain small and randomly oriented nanoparticles (i.e. high incoherent interface), generating highly strained nanoareas in the YBCO, with enhancement in the vortex pinning. We have also observed that the incoherent interface is not the only parameter controlling the nanostrain. The Cu?O intergrowth characteristics must also be a key factor for controlling the nanostrain in future tuning of YBCO vortex pinning.

We report on the spontaneous segregation of double perovskite Ba2YTaO6 (BYTO) nanoparticles within YBa2Cu3O7 (YBCO) films forming a nanocomposite with two ternary oxides by the low cost and scalable chemical solution trifluoroacetate approach. Phase orientation, nanostructural and pinning studies are carried out by 2D x-ray diffraction, advanced scanning transmission electron microscopy and transport measurements, respectively. In this complex oxide nanocomposite system (YBCO–BYTO) the majority of the nanoparticles segregated within the (00l)-oriented superconducting matrix are randomly oriented. The presence of randomly oriented nanoparticles plays a key role in the generation of localized highly strained areas within the YBCO matrix which are suggested to strongly affect the superconducting properties. The incorporation of 6–10% of BYTO resulted in a maximum pinning force, at 77 K, three times higher than that obtained for a pristine sample, while Tc was maintained at 89–90 K.

Thin, reinforced and biaxially textured Ni5W/Ni12W/Ni5W composite substrate for coated conductor applications has been fabricated by traditional powder metallurgy method using the sparking plasma sintering (SPS) technology, followed by cold rolling and annealing. In-situ EBSD strain-stress analysis shows that the yield stress (δ0.2) can reach 240MPa. The high quality of cubic texture and boundaries of low misorientation angle were stable until elongations as high as 2%. Meanwhile, the cubic grain fractions on surfaces of top Ni5W layer of the composite tapes are 98.3%, 99.5% and 99.8%, respectively, corresponding to be annealed at 1250°C for 60min, 120min and 180min, indicating the cube texture can successfully sustain after severe treatment condition.

Mechanically strengthened, highly cube textured Ni?7?at.%W/Ni?12?at.%W multi-layer substrates developed for coated conductors have been prepared by the advanced spark plasma sintering technique. The key innovation for developing this weakly magnetic and reinforced substrate was to use a new powder metallurgy and sintering route to bond multi-layers of Ni7W/Ni12W/Ni7W together in order to get an initial ingot, followed by the optimized cold working and annealing. Particular efforts were made in view of the optimization of the design, pressing as well as the heat treatment processes of the starting ingots to obtain a chemically gradient composite bulk, thus ensuring the subsequent cold deformation. The produced composite substrates have a strong {100} texture on Ni7W outer layers. The percentage of the biaxially orientated grains within a misorientation angle of 10? is as high as 97.5%, while the length percentage of low-angle grain boundaries ranging from 2? to 10? in the composite substrate reaches 87.2%. Moreover, the yield strength ?0.2 of the tape approaches 333?MPa, and the saturation magnetization is substantially reduced by 81.6% at 77?K when compared to that of a commercial used Ni5W substrate.

Mechanically strengthened, highly cube textured Ni-7at.%W/Ni-12at.%W multi-layer substrates used for coated conductors have been prepared by advanced spark plasma sintering technique. The key innovation for developing this weakly magnetic and reinforced substrate was to use a new powder metallurgy and sintering route to bond multi-layers of Ni7W-Ni12W-Ni7W together in order to get an initial ingot, then followed by optimized cold working and annealing. Particular efforts were made in view of the optimization of the design, pressing as well as the heat treatment processes of the starting ingots in order to obtain a chemically gradient composite bulk, thus ensuring the subsequent cold deformation of the bulk. The produced composite substrates have a strong {100} texture on the top Ni7W outer layer determined by EBSD and X-ray. The percentage of the biaxially orientated grains within a misorientation angle of 10° is as high as 97.5%, while the length percentage of low angle GBs ranging from 2° to 10° in the composite substrate reaches 87.2%. Moreover, the yield strength σ0.2 of the tape approaches 333 MPa, and the saturation magnetization is substantially reduced by 81.6% at 77K when compared to that of a commercial used Ni5W substrate.