Orbital Ordering Transition in Sr2VO4

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Orbital Ordering Transition in Sr2VO4
H. D. Zhou, B. S. Conner, L. Balicas, C. R.
Wiebe National High Magnetic Field
Laboratory/Florida State University
Layered perovskites are well-known to exhibit
various intriguing physical phenomena two
celebrated examples are high-temperature d-wave
superconductivity in the cuprates La2-xSrxCuO4
and low-temperature p-wave superconductivity in
Sr2RuO4. The search for exotic physics in s 1/2
systems has led to the synthesis of analogous
materials which retain the K2NiF4 structure.
Sr2VO4, which has a similar V4 (3d1) state as
Cu2 (3d9) and Ru4 (4d1) has been prepared. The
magnetic and low-temperature structural data on
this sample clearly show a orbital-ordering
transition at 97 K. The results experimentally
confirm the orbital-ordering state in Sr2VO4
predicted by first-principles calculations using
combinations of the local-density approximation
and the GW method.
High resolution X-ray diffraction to 10 K
The magnetic transition and the change in lattice
parameters at 97 K clearly show a orbital
ordering transition in Sr2VO4 with increased
occupancy of dxz/dyz orbitals
H. D. Zhou et al., Phys. Rev. Lett. 99, 136403
(2007)