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The hysteresis loss of Ni–5 at.%W (Ni5W) substrate contributes considerably to the alternating current (AC) loss of coated conductors (CCs) working at low transporting current or low-frequency field. In the present work, the evolution of texture and magnetic properties in Ni5W substrates is analyzed and also the relationship between magnetic properties and the extrinsic characteristics (evolved due to the processing techniques) is determined. By making the comparison, we discovered the magnetic domain structures of Ni5W substrates for the first time, achieving a strip/branched domain structures in the recrystallized substrates. The hysteresis loss has been decreased dramatically for the recrystallized substrates. Interestingly, we also observed that this loss is also related to the annealing temperature in the fully recrystallized substrates. The reduced loss can be mainly attributed toward the decrease of grain boundary, which proves the contribution of grain size toward the reduction of hysteresis loss. This result provides a new insight to tailor the hysteresis loss of Ni5W substrates used for coated conductors. [ABSTRACT FROM AUTHOR]

The formation of deformation and recrystallization textures has been investigated in a Ni7W alloy after heavy cold rolling and subsequent annealing at different temperatures. Cold rolling to a von Mises strain of 4.17 produced a mix of rolling texture that lies between classical brass- and copper-type rolling textures, with the fraction of S({123}<634>), brass({110}<112>), and copper({112}<111>) orientations being 33, 28, and 13%, respectively. The fraction of rolling texture for the deformed Ni7W alloy samples increased slightly during recovery, was then consumed significantly during recrystallization, and dropped to 22% after being annealed at 800 °C for 1 h. The fraction of cube({001}<100>) orientation increased to 26% after primary recrystallization, whereas other random orientations of 43% formed in the Ni7W alloy samples. Further annealing promoted cube grain growth, which lead to a significant strengthening of the cube texture and to a significant loss in high angle boundary (HAB). The fractions of cube texture and HAB of the Ni7W alloy substrate were 92.1 and 27.8%, respectively, after annealing at 1200 °C for 1 h. [ABSTRACT FROM PUBLISHER]

Abstract: This paper states the epitaxial growth of La2Zr2O7(LZO) buffer layers on the cube textured nickel alloy substrate, with the nitrate as the precursor. The solution stability and the heat treatment processing were discussed respectively. The solution of hydrated nitrates dissolved in ethanol being a sol at a higher temperature, the precursor was pre-dried and methanol was substituted with a higher dielectric constant. Because of the multi-step decomposition of the nitrates, a multi-step heat treatment route was followed, the complete decomposition of the intermediate phases being essential. The orientation analysis shows a cube textured film with the FWHM values of the (222) phi-scan and of the (400) ω-scan being 8.50° and 8.10° respectively. The SEM image shows a dense and homogeneous film without cracks and holes. The analysis above indicates that the present route is feasible for the preparation of LZO buffer layers [Copyright &y& Elsevier]

This paper focused on the modification properties of the La2Zr2O7 (LZO) seed layers for the epitaxial growth of thick LZO buffer films on cube-textured Ni5%W (Ni5W) substrate by the metal organic deposition (MOD) method. The surface morphologies of the LZO seed layers with different precursor concentrations were described by SEM. The grain orientation and the crystallographic growth model of the LZO seed layer were characterized by the electron backscatter diffraction (EBSD). The XRD analyses reveal that the LZO buffer layers on the Ni5W substrates with and without seed layers were grown epitaxially. However, the uniformly distributed islanded LZO seed layers with highly (001)[110] rotated cube texture not only can improve the crystallinity of the subsequent LZO buffer films, but also can optimize the in-plan and out-plan orientations of the thick LZO buffer layers. [ABSTRACT FROM AUTHOR]

CeO2 caped La2Zr2O7(LZO) buffer layers on cube-textured Ni5W substrates were fabricated by the method of chemical solution deposition(CSD). The orientation of both LZO film and CeO2 /LZO buffer layer was investigated using conventional XRD and X-ray four circle diffractometers, respectively. The results reveal that both the LZO film on Ni5W substrates and CeO2 film on LZO buffer layer are grown epitaxially. The value of Full Width at Half Maximum (FWHM) of (111) Phi scan of CeO2/LZO buffer layer is around 8°, and the FWHM of (200) w-scan of CeO2/La2Zr2O7 buffer layer is 6.5°, indicating a good in-plan orientation of the as obtained buffer layers. It was observed by the high resolution SEM that the surface of LZO buffer layer is crack-free and very dense. The surface result observed by AFM indicates a very smooth CeO2 surface with 5.9 nm of the root mean square roughness measured in an areas of 30 x 30 μm2. AES depth profile results of CeO2/LZO buffer layers shows that the deposited LZO film could effectively prevent the diffusion of Ni into the buffer layer. [ABSTRACT FROM AUTHOR]

A sharp cube textured alloy substrates with high strength and low magnetism are required in coated conductors' applications. In this work, the cube textured Ni-7at.%W substrates, starting from advanced powder metallurgy ingots followed by Rolling Assisted Biaxially Textured Substrate (RABiTS) method, have been prepared. The fabrication processes of Ni-7at.%W tapes with sharp cube texture by spark plasma sintering(SPS) routes were described. By Electron Back Scattering Diffraction (EBSD) analysis, the percentage of the cube texture component in Ni-7at. %W tape surface is found to reach 99.4% within a misorientation angle smaller than 10°. Moreover, the formation mechanism of the cube texture in the Ni-7at. %W tape was also investigated by EBSD. Particular attention was focused on the difference of the texture components along the thickness of the partially recrystallized samples. [ABSTRACT FROM AUTHOR]

Abstract: One of the main challenges for coated conductor applications is to produce sharp cubic textured alloy substrates with high strength and low magnetism. In this work, the cubic textured Ni–7at.%W substrates were prepared from different powder metallurgy ingots by rolling-assisted biaxially textured substrate processing. The fabrication processes of cubic texture in the Ni–7at.%W tapes by two powder metallurgy routes are described in detail. Through the optimized process, full width at half maximum values of 6.7° and 5.0° were obtained, as estimated by X-ray (111) phi scan and (200) rocking curve in the textured Ni–7at.%W tape, respectively. By electron backscattering diffraction (EBSD) analysis, the percentage of the cubic textured component in the Ni–7at.%W tape surface was found to reach 97.0% within a tolerance angle smaller than 10°. Moreover, the formation mechanism of the cubic texture in the Ni–7at.%W tape were also investigated by EBSD. Particular attention was focused on the difference in the texture components along the thickness of the partially recrystallized samples. [Copyright &y& Elsevier]

Abstract: A single Ce0.8Gd0.2O1.9 (CGO) buffer layer was successfully grown on the home-made textured Ni–5at.%W (Ni–5W) substrates for YBCO coated conductors by a simple metal–organic deposition (MOD) technique. The precursor solution was prepared using a newly developed process and only contained common metal–organic salts of both Ce and Gd dissolved into a propionic acid solvent. The precursor solution at 0.4M concentration was spin coated on short samples of Ni–5W substrates and heat-treated at 1100°C in a mixture gas of 5% H2 in Ar for an hour. X-ray studies indicated that the CGO films had good out-of-plane and in-plane textures with full-width-half-maximum values of 4.18° and 6.19°, respectively. Atomic force microscope (AFM) investigations of the CGO films revealed that most of the grain boundary grooves on the Ni–5W surface were found to be well covered by CGO layers, which had a fairly dense and smooth microstructure without cracks and porosity. These results indicate that our MOD technique is very promising for further development of single buffer layer architecture for YBCO coated conductors, due to its low cost and simple process. [Copyright &y& Elsevier]