Abstract
Chiral materials, where no improper symmetry operations such as inversion are present, are systems prone to the appearance of a skyrmion lattice. Recently it has been shown theoretically that not only ferromagnets (FMs) but also antiferromagnets (AFMs) can host such kind of phases. In this work we study a new candidate for AFM skyrmions, , by means of magnetization and specific heat measurements on poly and single crystals. X-ray diffraction confirms a trigonal chiral crystal structure, where europium ions form helices along the direction. In spite of predominantly FM interactions, ions order antiferromagnetically at K in what seems to be an incommensurate amplitude-modulated magnetic state where the moments are oriented mainly along the direction. A second magnetic transition takes place at K, involving the ordering of an in-plane component of the Eu moment likely resulting in an equal-moment structure. Specific heat data show a tail above . Accordingly the magnetic entropy at is strongly reduced in comparison to the expected value. This evidences a significant amount of frustration. A simple analysis based on a Heisenberg model indicates that the observed properties imply the presence of several relevant interactions, with competing FM and AFM ones resulting in frustration. Thus is a new interesting magnetic system, where chirality and frustration might result in unconventional magnetic textures.
- Received 7 December 2020
- Revised 25 May 2021
- Accepted 27 July 2021
DOI:https://doi.org/10.1103/PhysRevB.104.054416
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Open access publication funded by the Max Planck Society.
Published by the American Physical Society