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arXiv · 1008.3487

Magnetic phase diagram of the multiferroic FeTe$_2$O$_5$Br

M. Pregelj·A. Zorko·O. Zaharko·Z. Kutnjak·M. Jagodič·Z. Jagličić·H. Berger·M. de Souza·C. Balz·M. Lang·D. Arčon
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Abstract

The low-temperature magnetic phase diagram of the multiferroic system FeTe$_2$O$_5$Br down to 300 mK and up to 9 T is presented. Short-range magnetic correlations within the crystal layers start to develop already at $\sim$50 K, i.e., far above $T_{N1} \sim$ 11.0 K, where the system undergoes a magnetic phase transition into the high-temperature incommensurate (HT-ICM) phase. Only 0.5 K lower, at $T_{N2}$, the system undergoes a second phase transition into the low-temperature incommensurate amplitude-modulated (LT-ICM) phase accompanied by a spontaneous electric polarization. When the magnetic field is applied, the transition temperatures shift depending on the field orientation. In the case of $B||b$ and $B >$ 4.5 T, the HT-ICM phase disappears along with the electric polarization in the LT-ICM phase. The field dependence of the magnetic transition temperatures is explained in the context of the magnetic susceptibility behavior. Similarities and differences between the novel amplitude-modulated and well-established helicoidal magnetoelectrics are discussed.

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M. Pregelj, A. Zorko, O. Zaharko, Z. Kutnjak, M. Jagodič, Z. Jagličić, H. Berger, M. de Souza, C. Balz, M. Lang, D. Arčon. 2010-08-20. Magnetic phase diagram of the multiferroic FeTe$_2$O$_5$Br. https://doi.org/10.1103/physrevb.82.144438

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