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, ${\mathrm{EuIr}}_{2}{\mathrm{P}}_{2}$, 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 $c$ direction. In spite of predominantly FM interactions, ${\mathrm{Eu}}^{2+}$ ions order antiferromagnetically at ${T}_{{N}_{1}}=5$ K in what seems to be an incommensurate amplitude-modulated magnetic state where the moments are oriented mainly along the $c$ direction. A second magnetic transition takes place at ${T}_{{N}_{2}}=2.9$ 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 ${T}_{{N}_{1}}$. Accordingly the magnetic entropy at ${T}_{{N}_{1}}$ is strongly reduced in comparison to the expected $Rln8$ 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 ${\mathrm{EuIr}}_{2}{\mathrm{P}}_{2}$ is a new interesting magnetic system, where chirality and frustration might result in unconventional magnetic textures.
Highlights
Magnetic intermetallic systems based on rare-earth metals are usually described based on two magnetic couplings: the indirect Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction, which tends to order the system, and the Kondo effect which screens the moments at low temperature
In this context magnetic frustration arises as a new playground for exotic physics
Susceptibility and specific heat data both indicate a first magnetic transition to an AFM state at TN1 = 5 K followed by a second transition at TN2 = 2.9 K from an AFM1 to an AFM2 state
Summary
Magnetic intermetallic systems based on rare-earth metals are usually described based on two magnetic couplings: the indirect Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction, which tends to order the system, and the Kondo effect which screens the moments at low temperature The interplay between these two couplings can be represented in the so-called Doniach phase diagram [1,2], where interesting phenomena appear as a function of a nonthermal tuning parameter, such as unconventional superconductivity and non-Fermi-liquid behavior [3,4]. The first experimental identification of such kind of phase on a bulk material was reported on metallic MnSi [10,11], and later Fe0.8Co0.2Si [12] and Cu2OSeO3 were identified as skyrmion-hosting bulk compounds [13,14] All of these ferromagnetic systems crystallize in the same crystal structure, space group P213, which is one of the few that lacks a center of inversion and all kinds of improper symmetry operations. We present in this work the synthesis of polycrystalline and single-crystal samples of EuIr2P2 and the study of the magnetic properties by means of magnetization and specific heat measurements
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
