Chemical synthesis of nanoparticles for artificial pinning centers in YBCO coated conductors
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C7.10.1
Chemical synthesis of nanoparticles for artificial pinning centers in YBCO coated conductors Srivatsan Sathyamurthy, Keith J. Leonard and M. Parans Paranthaman Oak Ridge National Laboratory, Oak Ridge, TN 37831
Abstract Ceria nanoparticles were prepared using a solution based approach using cerium (III) acetate as a starting material and cetyltrimethylammonium hydroxide (CTAOH) as a precipitating agent and surfactant. The presence of the surfactant CTAOH helps prevent agglomeration of the nanoparticles. Using X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM), the particle size was determined to be 3.5 – 4 nm. The structure and properties of these CeO2 nanoparticles have been analyzed. Introduction Second generation coated conductors (2G wires) have brought high temperature superconductors (HTS) closer to practical usage in electrical power applications with improved performance, at lower cost along with significant environmental benefits. An important goal for improved performance and lower fabrication costs in these coated conductors is to achieve enhanced flux-pinning in these materials in a practical way. Flux pinning is crucially important in practical conductors as it enables large supercurrent conduction in the presence of magnetic fields – a property that is essential for several applications such as motors, generators, etc. Judith Driscoll and co-workers [1] have already reported that incorporation of BaZrO3 nanoparticles into the YBCO microstructure during film growth serves to significantly enhance flux pinning. Goyal et al [2] have demonstrated that incorporation of BaZrO3, CaZrO3, and YSZ nanoparticles in the form of self-aligned nanodots significantly enhances pinning properties by several orders of magnitude in both H//c and H//ab directions. All these results are based on the use of Pulsed Laser Deposition (PLD) for the YBCO films. Cerium oxide, CeO2 nanoparticles have been extensively investigated for a wide variety of applications such as catalysis [3], fuel cells [4], polishing media in microelectronics, luminescent materials [5], etc., and could potentially be used as artificial pinning centers in high temperature superconductors. The physical and chemical properties of nanometer (nm) sized particles are significantly different from those of the bulk material. Ultrafine particles of CeO2 have great potential for use as UV absorbent materials and high activity catalysts. Many researchers have prepared cerium oxide nanoparticles using various methods such as gas condensation of Ce metal followed by oxidation using O2 gas [6], homogeneous precipitation using hexamethylenetetramine [7], sol-gel processing [8], hydrothermal synthesis technique [9], and electrochemical synthesis [10]. In this work, we explore synthesis of nanoparticles using a solution based approach. Synthesis of nanoparticles of CeO2, BaCeO3, BaZrO3 etc using various solution based approaches are currently being explored [11, 12]. In this paper, we report on the results obtained from the sy
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