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arXiv · 1208.6182

Weak ferromagnetism and internal magnetoelectric effect in LiFeP$_2$O$_7$

K. -C. Liang·W. Zhang·B. Lorenz·Y. Y. Sun·P. S. Halasyamani·C. W. Chu
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Abstract

The magnetic, thermodynamic, and pyroelectric properties of LiFeP$_2$O$_7$ single crystals are investigated with emphasis on the magnetoelectric interaction of the electrical polarization with the magnetic order parameter. The magnetic order below T$_N\simeq$ 27 K is found to be a canted antiferromagnet with a weak ferromagnetic component along the $b-$axis. A sharp peak of the pyroelectric current at T$_N$ proves the strong internal magnetoelectric interaction resulting in a sizable polarization decrease at the onset of magnetic order. The magnetoelectric effect in external magnetic fields combines a linear and a quadratic field dependence below T$_N$. Thermal expansion data show a large uniaxial magnetoelastic response and prove the existence of strong spin lattice coupling. LiFeP$_2$O$_7$ is a polar compound with a strong interaction of the magnetic order parameter with the electric polarization and the lattice.

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K. -C. Liang, W. Zhang, B. Lorenz, Y. Y. Sun, P. S. Halasyamani, C. W. Chu. 2012-08-30. Weak ferromagnetism and internal magnetoelectric effect in LiFeP$_2$O$_7$. https://doi.org/10.1103/physrevb.86.094414

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