Selective Occupancy of Sites by Rare Earths in K2Nd(1-X)EuxNb5O15 Nanopowders, where X = 0, 0.0025, 0.025, 0.05 and 0.1, Prepared by Modified Polyol Method

Eliane Ayumi Namikuchi; Marcos Augusto Lima Nobre; Silvania Lanfredi

doi:10.4028/www.scientific.net/MSF.820.361

Paper Titles

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PP/EPDM Blends Compatibilized by Organically Modified Clays
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Selective Occupancy of Sites by Rare Earths in K₂Nd_(1-X)Eu_xNb₅O₁₅ Nanopowders, where X = 0, 0.0025, 0.025, 0.05 and 0.1, Prepared by Modified Polyol Method
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Particle Size Analysis of Fe₃O₄ Nanoparticles Coated by Polyethyleneglycol
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New Additive Type Amorphous-Carbon/Zn Modifier of the Thermal Conductivity of Alcohol Fuel
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Selective Occupancy of Sites by Rare Earths in K₂Nd_(1-X)Eu_xNb₅O₁₅ Nanopowders, where X = 0, 0.0025, 0.025, 0.05 and 0.1, Prepared by Modified Polyol Method

Abstract:

Niobates with tetragonal tungsten bronze TTB-type structure have presented great technological potential due to their dielectric, ferroelectric, pyroelectric properties. The preparation by the modified polyol method and structural characterization of K₂Nd_(1-x)Eu_xNb₅O₁₅ nanopowders, where x = 0; 0.0025; 0.025; 0.05 e 0.1, were investigated. The structural parameters were analyzed as a function of concentration of europium ions in the K₂NdNb₅O₁₅ host structure using the Rietveld method. From structural parameters was determined the TTB-type structure with tetragonal symmetry, where the pentagonal sites is occupied by K⁺ and Eu³⁺ ions and tetragonal sites is occupied only by Nd³⁺ ions. The addition of europium in the host structure led to a decrease in the lattice parameters, compatible with the increasing degree of distortion of NbO6 polyhedra. The average crystallite size showed values between 18.25 and 26nm.