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Full-Text Articles in Engineering
Novel Yttrium-Stabilized Zirconia Polymeric Precursor For The Fabrication Of Thin Films, Roger M. Smith, X.-D. Zhou, Wayne Huebner, Harlan U. Anderson
Novel Yttrium-Stabilized Zirconia Polymeric Precursor For The Fabrication Of Thin Films, Roger M. Smith, X.-D. Zhou, Wayne Huebner, Harlan U. Anderson
Materials Science and Engineering Faculty Research & Creative Works
An acetate-based polymeric precursor for producing yttrium-stabilized zirconia (YSZ) was developed. The precursor was prepared under ambient conditions and contains only yttrium and zirconium cations. Dense, crack-free films were fabricated with this precursor on alumina substrates at a rate of 60 nm per deposition, producing polycrystalline YSZ at temperatures as low as 600 °C. Grain growth in thin YSZ films followed Arrhenius equation with an activation energy approximately 0.45 eV. The residual strain in YSZ films decreased with increasing annealing temperature from 600 to 900 °C.
In-Plane Anisotropy And Temperature Dependence Of Oxygen Phonon Modes In Yba₂Cu₃O₆.₉₅, Jaeho Chung, Takeshi Egami, R. J. Mcqueeney, Mohana Yethiraj, Masatoshi Arai, Tetsuya Yokoo, Yu Nikolaijevitsch Petrov, Herbert A. Mook, Yasuo Endoh, Setsuko Tajima, Christopher D. Frost, Fatih Dogan
In-Plane Anisotropy And Temperature Dependence Of Oxygen Phonon Modes In Yba₂Cu₃O₆.₉₅, Jaeho Chung, Takeshi Egami, R. J. Mcqueeney, Mohana Yethiraj, Masatoshi Arai, Tetsuya Yokoo, Yu Nikolaijevitsch Petrov, Herbert A. Mook, Yasuo Endoh, Setsuko Tajima, Christopher D. Frost, Fatih Dogan
Materials Science and Engineering Faculty Research & Creative Works
Inelastic pulsed neutron scattering measurements on YBa2Cu3O6.95 single crystals indicate that the sample has a distinct a-b plane anisotropy in the oxygen vibrations. The Cu-O bond-stretching-type phonons, which are suspected to interact strongly with charge, are simultaneously observed along the a and b directions due to a 7-meV splitting arising from the orthorhombicity, even though the sample is twinned. The bond-stretching LO branch with the polarization along a (perpendicular to the chain) loses intensity beyond the middle of the zone, indicating branch splitting as seen in doped nickelates, with the second branch being located at …
Observation Of Changes In The Atomic And Electronic Structure Of Single-Crystal Yba₂Cu₃O₆.₆ Accompanying Bromination, Lamine M. Dieng, Yasuhiro Inamura, Trevor A. Tyson, Mark C. Croft, Fatih Dogan, C. Y. Kim, Joseph C. Woicik, James M. Grow
Observation Of Changes In The Atomic And Electronic Structure Of Single-Crystal Yba₂Cu₃O₆.₆ Accompanying Bromination, Lamine M. Dieng, Yasuhiro Inamura, Trevor A. Tyson, Mark C. Croft, Fatih Dogan, C. Y. Kim, Joseph C. Woicik, James M. Grow
Materials Science and Engineering Faculty Research & Creative Works
To ascertain the role of bromination in the recovery of superconductivity in underdoped YBa2Cu3O6+y (YBCO), we have performed polarized multiple-edge x-ray-absorption fine structure (XAFS) measurements on normal (y~0.6) and brominated (Br/Cu~1/30, y~0.6) single crystals with superconducting transitions at 63 and 89 K, respectively. The brominated sample becomes strongly heterogeneous on an atomic length scale. Approximately one-third of YBCO is locally decomposed yet incorporated as a well-ordered "host" lattice as nanoscale regions. The decomposed phase consists of heavily distorted domains with an order not following that of the "host" lattice. Structurally, these domains are fragments of …
Observation Of Magnetic Moments In The Superconducting State Of Yba₂Cu₃O₆.₆, Herbert A. Mook, Pengcheng Dai, Fatih Dogan
Observation Of Magnetic Moments In The Superconducting State Of Yba₂Cu₃O₆.₆, Herbert A. Mook, Pengcheng Dai, Fatih Dogan
Materials Science and Engineering Faculty Research & Creative Works
Neutron scattering measurements for YBa2Cu3O6.6 have identified small magnetic moments that increase in strength as the temperature is reduced below T* and further increase below Tc. An analysis of the data shows the moments are antiferromagnetic between the Cu-O planes with a correlation length of longer than 195 Å in the a-b plane and about 35 Å along the c axis. The origin of the moments is unknown, and their properties are discusssed both in terms of Cu spin magnetism and orbital bond currents.
Evolution Of The Resonance And Incommensurate Spin Fluctuations In Superconducting Yba₂Cu₃O₆₊ₓ, Pengcheng Dai, Herbert A. Mook, Rodney Dale Hunt, Fatih Dogan
Evolution Of The Resonance And Incommensurate Spin Fluctuations In Superconducting Yba₂Cu₃O₆₊ₓ, Pengcheng Dai, Herbert A. Mook, Rodney Dale Hunt, Fatih Dogan
Materials Science and Engineering Faculty Research & Creative Works
Polarized and unpolarized neutron triple-axis spectrometry was used to study the dynamical magnetic susceptibility Χ″(q, ω) as a function of energy (ℏ ω) and wave vector (q) in a wide temperature range for the bilayer superconductor YBa2Cu3O6+x with oxygen concentrations, x, of 0.45, 0.5, 0.6, 0.7, 0.8, 0.93, and 0.95. The most prominent features in the magnetic spectra include a spin gap in the superconducting state, a pseudogap in the normal state, the much-discussed resonance, and incommensurate spin fluctuations below the resonance. We establish the doping dependence of the spin gap in the superconducting state, …