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arXiv · 1601.04430

Incommensurate spin-density-wave antiferromagnetism in CeRu$_2$Al$_2$B

A. Bhattacharyya·D. D. Khalyavin·F. Krüger·D. T. Adroja·A. M. Strydom·W. A. Kockelmann·A. D . Hillier
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Abstract

The newly discovered Ising-type ferromagnet CeRu$_2$Al$_2$B exhibits an additional phase transition at $T_\textrm{N}$ = 14.2 K before entering the ferromagnetic ground state at $T_\textrm{C}$ = 12.8 K. We clarify the nature of this transition through high resolution neutron diffraction measurements. The data reveal the presence of a longitudinal incommensurate spin-density wave (SDW) in the temperature range of $T_\textrm{C}<T<T_\textrm{N}$. The propagation vector ${\bf q} \sim (0,0,0.148)$ is nearly temperature independent in this region and discontinuously locks into ${\bf q} = 0$ at $T_\textrm{C}$. Mean-field calculations of an effective Ising model indicate that the modulated SDW phase is stabilized by a strong competition between ferromagnetic and antiferromagnetic exchange interactions. This makes CeRu$_2$Al$_2$B a particularly attractive model system to study the global phase diagram of ferromagnetic heavy-fermion metals under influence of magnetic frustration.

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A. Bhattacharyya, D. D. Khalyavin, F. Krüger, D. T. Adroja, A. M. Strydom, W. A. Kockelmann, A. D . Hillier. 2016-01-18. Incommensurate spin-density-wave antiferromagnetism in CeRu$_2$Al$_2$B. https://doi.org/10.1103/physrevb.93.060410

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