Synchrotron X-ray powder diffraction and convergent beam electron diffraction studies on the cubic phase of MgV{sub 2}O{sub 4} spinel

Journal Article · Tue Jul 01 00:00:00 EDT 2014 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2014.03.037· OSTI ID:22334279

Niitaka, Seiji ^[1]; Lee, Soyeon ^[2]; Oshima, Yoshifumi ^[3]; Kato, Kenichi ^[4]; Hashizume, Daisuke ^[5]; Takata, Masaki ^[4]; Takagi, Hidenori ^[1]

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1. RIKEN, 2-1, Hirosawa, Wako, Saitama 351-0198 (Japan)
2. Tokyo Institute of Technology, 2-12-1 Oh-okayama, Meguro-ku, Tokyo 152-8551 (Japan)
3. Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, Osaka, Ibaraki 567-0047 (Japan)
4. RIKEN SPring-8 Center, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)
5. RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

The A V{sub 2}O{sub 4} (A=Mg{sup 2+}, Zn{sup 2+}, Cd{sup 2+}) spinels are three-dimensional spin-1 frustrated systems with orbital degree of freedom, which have been known to possess intriguing orbital states causing releases of spin frustration at low temperatures. We have performed synchrotron X-ray and convergent beam electron diffraction measurements for one of these vanadates, MgV{sub 2}O{sub 4} in order to clarify its crystal structure in the high temperature cubic phase, which is regarded as an important starting point for understanding the details of the low temperature phase. We have successfully observed that the [001] zone axis convergent beam electron diffraction pattern exhibits 4mm symmetry, suggesting the space group of Fd3{sup ¯}m in the cubic MgV{sub 2}O{sub 4}. It has also been demonstrated that the crystal structure of the cubic MgV{sub 2}O{sub 4} contains VO{sub 6} octahedra elongated along the threefold rotation axis. Based on our results, we discuss the orbital states of MgV{sub 2}O{sub 4} as well as the other spinel vanadates. - Graphical abstract: Precise geometry of the VO{sub 6} octahedra in the cubic phase of MgV{sub 2}O{sub 4} spinel determined with the synchrotron powder XRD data. - Highlights: • We examined the crystal structure of the cubic phase of MgV{sub 2}O{sub 4} spinel. • We prepared the single crystal and powdered sample of MgV{sub 2}O{sub 4} with high quality. • The result of the CBED measurement agrees with the space group of Fd3{sup ¯}m in the phase. • The cubic phase has VO{sub 6} octahedra elongated along the threefold rotation axis.

• OSTI ID: 22334279
• Journal Information: Journal of Solid State Chemistry, Vol. 215; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CADMIUM IONS
CUBIC LATTICES
DEGREES OF FREEDOM
ELECTRON BEAMS
ELECTRON DIFFRACTION
MONOCRYSTALS
SPACE GROUPS
SPIN
SPINELS
SYNCHROTRONS
VANADATES
X RADIATION
X-RAY DIFFRACTION
ZINC IONS