Publication Date:
2017-04-29
Description:
Author(s): L. J. Bannenberg, K. Kakurai, P. Falus, E. Lelièvre-Berna, R. Dalgliesh, C. D. Dewhurst, F. Qian, Y. Onose, Y. Endoh, Y. Tokura, and C. Pappas Chiral magnetism plays an increasingly important role in condensed matter investigations driven by the discovery of exotic spin textures, such as the topologically protected chiral skyrmions that can form a lattice under magnetic fields. The nature and universality of the phase diagram in cubic chiral magnets has been the subject of numerous experimental and theoretical investigations, including the transition to the helimagnetic state. In MnSi, the archetypal system in this family, this transition is of first order and involves a precursor phase, where strong chiral fluctuating correlations build up. This work presents an experimental investigation of the structural and dynamical aspects of the phase transition in Fe 1 − x Co x Si, a system that belongs to the same family as MnSi but with the additional possibility to tune important physical interactions and parameters through variation of the Fe and Co concentration. In this system, the combination of small-angle neutron scattering and neutron spin echo spectroscopy uncovers that the scenario of the transition is qualitatively very different from that in MnSi. This goes beyond what can be expected from a comparison of the relevant length scales and thus challenges the validity of a universal approach to the helimagnetic transition in cubic chiral magnets. [Phys. Rev. B 95, 144433] Published Fri Apr 28, 2017
Keywords:
Magnetism
Print ISSN:
1098-0121
Electronic ISSN:
1095-3795
Topics:
Physics
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