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The structural features of the charge ordering states in LuFe2O4 are characterized by in-situ cooling TEM observations from 300K down to 20K. Two distinctive structural modulations, a major q1= (1/3, 1/3, 2) and a weak q2=q1/10 + (0, 0,…

Materials Science · Physics 2009-11-13 Y. Zhang , H. X. Yang , C. Ma , H. F. Tian , J. Q. Li *

Measurements of the electrical and thermal conductivities, thermopower and paramagnetic susceptibility have been performed on single crystal samples of Bi1/2Sr1/2MnO3 and complemented with the X-ray powder diffraction data. A pronounced…

Strongly Correlated Electrons · Physics 2009-11-07 J. Hejtmanek , K. Knizek , Z. Jirak , M. Hervieu , C. Martin , M. Nevriva , P. Beran

We present the refinement of the crystal structure of charge-ordered LuFe2O4, based on single-crystal x-ray diffraction data. The arrangement of the different Fe-valence states, determined with bond-valence-sum analysis, corresponds to a…

Strongly Correlated Electrons · Physics 2012-05-04 J. de Groot , T. Mueller , R. A. Rosenberg , D. J. Keavney , Z. Islam , J. -W. Kim , M. Angst

We show that in mixed-valence 3d transition metal oxides undergoing a structural transition, the low temperature phase results from an effective ordering of the charge. This arrangement and the quantitative evaluation of the atomic charges…

Materials Science · Physics 2007-05-23 Y. Joly , S. Grenier , J. E. Lorenzo

The temperature dependence of charge order in Fe2OBO3 was investigated by resistivity and differential scanning calorimetry measurements, Mossbauer spectroscopy, and synchrotron x-ray scattering, revealing an intermediate phase between room…

Strongly Correlated Electrons · Physics 2007-12-19 M. Angst , R. P. Hermann , W. Schweika , J. -W. Kim , P. Khalifah , H. J. Xiang , M. -H. Whangbo , D. -H. Kim , B. C. Sales , D. Mandrus

We show that the valence electrons of Ba3NaRu2O9, which has a quasi-molecular structure, completely crystallize below 210 K. Using an extended Hubbard model, we show that the charge ordering instability results from long-range Coulomb…

X-ray scattering by multiferroic LuFe2O4 is reported. Below 320 K, superstructure reflections indicate an incommensurate charge order with propagation close to (1/3,1/3,3/2). The corresponding charge configuration, also found by electronic…

At ambient temperatures, CeRuSn exhibits an extraordinary structure with a coexistence of two types of Ce ions in a metallic environment, namely trivalent Ce3+ and intermediate valent Ce(4-x)+. Charge ordering produces a doubling of the…

Strongly Correlated Electrons · Physics 2012-02-24 R. Feyerherm , E. Dudzik , S. Valencia , J. A. Mydosh , Y. -K. Huang , W. Hermes , R. Pöttgen

High energy x-ray diffraction is used to investigate the bulk oxygen ordering properties of YBa_2Cu_3O_{6+x}. Superstructures of Cu-O chains aligned along the b axis and ordered with periodicity ma, along the a axis have been observed. For…

Electron microdiffraction study of phase transition in La2/3Ca1/3MnO3 revealed temperature dependent (h+1/2,0,l) diffraction spots. Their intensity peaks at Tc. Quantitative electron diffraction intensity analysis shows that they come from…

Strongly Correlated Electrons · Physics 2009-10-31 J. M. Zuo , J. Tao

We report a comprehensive neutron diffraction study of the crystal structure and magnetic order in a series of single-crystal and powder samples of SrFeO$_{3-\delta}$ in the vacancy range $0 \leq \delta \leq 0.23$. The data provide detailed…

Strongly Correlated Electrons · Physics 2015-06-05 M. Reehuis , C. Ulrich , A. Maljuk , Ch. Niedermayer , B. Ouladdiaf , A. Hoser , T. Hofmann , B. Keimer

Charge ordering in the low-temperature monoclinic structure of iron oxoborate (Fe2OBO3) is investigated using the local spin density approximation (LSDA)+U method. While the difference between t_{2g} minority occupancies of Fe^{2+} and…

Strongly Correlated Electrons · Physics 2016-11-02 I. Leonov , A. N. Yaresko , V. N. Antonov , J. P. Attfield , V. I. Anisimov

Single crystal X-ray diffraction measurements were performed on one-dimensional mixed valence vanadium bronze $\beta$-SrV$_6$O$_{15}$ in which a metal-insulator transition exists at 170 K. Above 170 K the P2$_1$/a structure with zigzag…

Strongly Correlated Electrons · Physics 2009-11-10 Claire Sellier , Florent Boucher , Etienne Janod

Microstructure properties, phase transitions, and charge ordering in the LuFe2O4 materials have been extensively investigated by means of transmission electron microscopy (TEM). The (001) twins as a common defect frequently appear in the…

Strongly Correlated Electrons · Physics 2007-05-23 Y. Zhang , H. X. Yang , C. Ma , H. F. Tian , J. Q. Li *

A combined neutron and x-ray diffraction study of TbBaFe2O5 reveals a rare checkerboard to charge ordering transition. TbBaFe2O5 is a mixed valent compound where Fe2+/Fe3+ ions are known to arrange into a stripe charge-ordered state below…

Strongly Correlated Electrons · Physics 2013-02-07 D. K. Pratt , S. Chang , W. Tain , A. A. Taskin , Yoichi Ando , J. L. Zarestky , A. Kreyssig , A. I. Goldman , R. J. McQueeney

Low as well as high-temperature electron and x-ray diffraction studies have been carried out on a rare-earth free B-site disordered electron-doped manganite SrMn0.875.Mo0.125O3-{\delta} in the temperature range of 83K to 637K. These studies…

Strongly Correlated Electrons · Physics 2015-03-23 Aga Shahee , N. P. Lalla

Charge ordering behavior is observed in the crystal prepared through the immersion of the $Na_{0.41}CoO_2$ crystal in distilled water. Discovery of the charge ordering in the crystal with Na content less than 0.5 indicates that the…

Materials Science · Physics 2016-08-31 C. H. Wang , H. T. Zhang , X. X. Lu , G. Wu , J. Q. Li , X. H. Chen

Since the discovery of charge disproportionation in the FeO$_2$ square-lattice compound Sr$_3$Fe$_2$O$_7$ by M\"ossbauer spectroscopy more than fifty years ago, the spatial ordering pattern of the disproportionated charges has remained…

We have investigated the charge and spin ordering in Nd{1/3}Sr{2/3}FeO{3} with neutron diffraction technique. This sample undergoes a charge ordering transition accompanying charge disproportionation of 2Fe4+ -> Fe3+ + Fe5+. We measured the…

Strongly Correlated Electrons · Physics 2009-10-31 R. Kajimoto , Y. Oohara , M. Kubota , H. Yoshizawa , S. K. Park , Y. Taguchi , Y. Tokura

X-ray diffraction experiments were performed on polycrystalline and single-crystal specimens of Ce$_{2}$Fe$_{17}$ at temperatures between 10 K and 300 K. Below $T_{\mathrm{t}}$ = 118$\pm$2 K, additional weak superstructure reflections were…

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