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Iowa State University

Series

Metallurgy

Physics and Astronomy

2008

Articles 1 - 4 of 4

Full-Text Articles in Physics

Magnetic Structure Of Dy3+ In Hexagonal Multiferroic Dymno3, Shibabrata Nandi, Andreas Kreyssig, J.-Q. Yan, Matthew D. Vannette, J. C. Lang, L. Tan, J. W. Kim, Ruslan Prozorov, Thomas A. Lograsso, Robert J. Mcqueeney, Alan I. Goldman Aug 2008

Magnetic Structure Of Dy3+ In Hexagonal Multiferroic Dymno3, Shibabrata Nandi, Andreas Kreyssig, J.-Q. Yan, Matthew D. Vannette, J. C. Lang, L. Tan, J. W. Kim, Ruslan Prozorov, Thomas A. Lograsso, Robert J. Mcqueeney, Alan I. Goldman

Ames Laboratory Publications

Element specific x-ray resonant magnetic scattering (XRMS) investigations were undertaken to determine the magnetic structure of the multiferroic compound, hexagonal DyMnO3. In the temperature range from 68 K down to 8 K the Dy3+ moments are aligned and antiferromagnetically correlated in the c direction according to the magnetic representation Γ3. The temperature dependence of the observed intensity can be modeled assuming the splitting of ground-state doublet crystal-field levels of Dy3+ by the exchange field of Mn3+. XRMS together with magnetization measurements indicate that the magnetic representation is Γ2 below 8 K.


Structural Transition And Anisotropic Properties Of Single-Crystalline Srfe2as2, J.-Q. Yan, Andreas Kreyssig, Shibabrata Nandi, N. Ni, Sergey L. Bud'ko, Robert J. Mcqueeney, R. William Mccallum, Thomas A. Lograsso, Alan I. Goldman, Paul C. Canfield Jul 2008

Structural Transition And Anisotropic Properties Of Single-Crystalline Srfe2as2, J.-Q. Yan, Andreas Kreyssig, Shibabrata Nandi, N. Ni, Sergey L. Bud'ko, Robert J. Mcqueeney, R. William Mccallum, Thomas A. Lograsso, Alan I. Goldman, Paul C. Canfield

Ames Laboratory Publications

Platelike single crystals of SrFe2As2 as large as 3×3×0.5 mm3 have been grown out of Sn flux. The SrFe2As2 single crystals show a structural phase transition from a high-temperature tetragonal phase to a low-temperature orthorhombic phase at To=198 K, and do not show any sign of superconductivity down to 1.8 K. The structural transition is accompanied by an anomaly in the electrical resistivity, Hall resistivity, specific heat, and the anisotropic magnetic susceptibility. In an intermediate temperature range from 198 to 160 K, single-crystal x-ray diffraction suggests a coexistence ...


Spin-Flop Transition In Gd5ge4 Observed By X-Ray Resonant Magnetic Scattering And First-Principles Calculations Of Magnetic Anisotropy, L. Tan, Andreas Kreyssig, Shibabrata Nandi, S. Jia, Yongbin Lee, J. C. Lang, Z. Islam, Thomas A. Lograsso, Deborah L. Schlagel, Vitalij K. Pecharsky, Karl A. Gschneidner Jr., Paul C. Canfield, Bruce N. Harmon, Robert J. Mcqueeney, Alan I. Goldman Feb 2008

Spin-Flop Transition In Gd5ge4 Observed By X-Ray Resonant Magnetic Scattering And First-Principles Calculations Of Magnetic Anisotropy, L. Tan, Andreas Kreyssig, Shibabrata Nandi, S. Jia, Yongbin Lee, J. C. Lang, Z. Islam, Thomas A. Lograsso, Deborah L. Schlagel, Vitalij K. Pecharsky, Karl A. Gschneidner Jr., Paul C. Canfield, Bruce N. Harmon, Robert J. Mcqueeney, Alan I. Goldman

Ames Laboratory Publications

X-ray resonant magnetic scattering was employed to study a fully reversible spin-flop transition in orthorhombic Gd5Ge4 and to elucidate details of the magnetic structure in the spin-flop phase. The orientation of the moments at the three Gd sites flop 90° from the c axis to the a axis when a magnetic field, Hsf=9 kOe, is applied along the c axis at T=9 K. The magnetic space group changes from Pnm′a to Pn′m′a′ for all three Gd sublattices. The magnetic anisotropy energy determined from experimental measurements is in good agreement with the ...


17o And 51v Nmr For The Zigzag Spin-1 Chain Compound Cav2o4, X. Zong, B. J. Suh, A. Niazi, J.-Q. Yan, Deborah L. Schlagel, Thomas A. Lograsso, David C. Johnston Jan 2008

17o And 51v Nmr For The Zigzag Spin-1 Chain Compound Cav2o4, X. Zong, B. J. Suh, A. Niazi, J.-Q. Yan, Deborah L. Schlagel, Thomas A. Lograsso, David C. Johnston

Ames Laboratory Publications

51V NMR studies on CaV2O4 single crystals and 17O NMR studies on 17O-enriched powder samples are reported. The temperature dependences of the 17O NMR linewidth and nuclear spin-lattice relaxation rate give strong evidence for a long-range antiferromagnetic transition at TN=78 K in the powder. Magnetic susceptibility measurements show that TN=69 K in the crystals. A zero-field 51V NMR signal was observed at low temperatures (f≈237 MHz at 4.2 K) in the crystals. The field-swept spectra with the field in different directions suggest the presence of two antiferromagnetic substructures. Each substructure is ...