New features in the phase diagram of TbMnO${}_3$

Abstract

The (H,T)-phase diagram of the multiferroic perovskite TbMnO${}_3$ was studied by high-resolution thermal expansion $\alpha (T)$ and magnetostriction $\Delta L(H)/L$ measurements. Below $T_N\simeq 42$ K, TbMnO${}_3$ shows antiferromagnetic order, which changes at $T_{FE}\simeq 28$ K where simultaneously a spontaneous polarization $P||c$ develops. Sufficiently high magnetic fields applied along $a$ or $b$ induce a polarization flop to $P||a$. We find that all of these transitions are strongly coupled to the lattice parameters. Thus, our data allow for a precise determination of the phase boundaries and also yield information about their uniaxial pressure dependencies. The strongly hysteretic phase boundary to the ferroelectric phase with $P||a$ is derived in detail. Contrary to previous reports, we find that even in high magnetic fields there are no direct transitions from this phase to the paraelectric phase. We also determine the various phase boundaries in the low-temperature region related to complex reordering transitions of the Tb moments.

17 pages including 9 figures

References in corpus (4)

• Spin current and magneto-electric effect in non-collinear magnets
• Multiferroics: different ways to combine magnetism and ferroelectricity
• A New Multiferroic Material: MnWO4
• Neutron diffraction study of TbMnO3: Magnetic structure revisited

Cited by in corpus (4)

• Ferromagnetism and increased ionicity in epitaxially grown TbMnO3 films
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• Field dependence of magnetic correlations through the polarization flop transition in multiferroic TbMnO3 : evidence for a magnetic memory effect
• Giant electro-thermal conductivity and spin-phonon coupling in an antiferromagnetic oxide