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arXiv · 0808.2759

Anharmonic effect on lattice distortion, orbital ordering and magnetic properties in Cs2AgF4

Da-Yong Liu·Feng Lu·Liang-Jian Zou
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Abstract

We develop the cluster self-consistent field method incorporating both electronic and lattice degrees of freedom to study the origin of ferromagnetism in Cs$_{2}$AgF$_{4}$. After self-consistently determining the harmonic and anharmonic Jahn-Teller distortions, we show that the anharmonic distortion stabilizes the staggered x$^{2}$-z$^{2}$/y$^{2}$-z$^{2}$ orbital and ferromagnetic ground state, rather than the antiferromagnetic one. The amplitudes of lattice distortions, Q$_{2}$ and Q$_{3}$, the magnetic coupling strengthes, J$_{x,y}$, and the magnetic moment, are in good agreement with the experimental observation.

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Da-Yong Liu, Feng Lu, Liang-Jian Zou. 2008-08-20. Anharmonic effect on lattice distortion, orbital ordering and magnetic properties in Cs2AgF4. https://doi.org/10.1088/0953-8984%2F21%2F2%2F026014

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