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arXiv · 0909.4494

Stabilization of charge and orbital ordered states by antiferromagnetism in the A-site ordered YBaMn2O6

X. N. Zhang·K. -Y. Choi·P. Lemmens·T. Nakajima·Y. Ueda
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Abstract

We report on Raman scattering measurements of the A-site ordered YBaMn2O6 in the wide temperature range of 10-650K. Upon cooling almost all phonon modes show pronounced temperature dependencies of frequency, linewidth, and scattering intensity. This suggests that the octahedra tilting, Mn-O bond angles and lengths vary with temperature in a concerted way. The remarkable feature is that the high-temperature metallic and the charge and orbital ordered (CO-OO) states coexist down to T_N=195K. In the antiferromagnetic state zone-folded modes are induced by the CO-OO superstructure and the phonon modes undergo an anomalous softening and narrowing. Our results evidence that the CO-OO state is stabilized by the spin ordering for temperatures below T_N.

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X. N. Zhang, K. -Y. Choi, P. Lemmens, T. Nakajima, Y. Ueda. 2009-09-29. Stabilization of charge and orbital ordered states by antiferromagnetism in the A-site ordered YBaMn2O6. https://arxiv.org/abs/0909.4494

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