Magnetism in EuAlSi and the Eu1-xSrxAlSi Solid Solution

作     者：Walicka, Dorota I. Blacque, Olivier Gornicka, Karolina White, Jonathan S. Klimczuk, Tomasz von Rohr, Fabian O. 

作者机构：Department of Quantum Matter Physics University of Geneva GenevaCH-1211 Switzerland Department of Chemistry University of Zurich ZurichCH-8057 Switzerland Laboratory for Neutron Scattering and Imaging PSI Center for Neutron and Muon Sciences PSI Villigen5232 Switzerland Faculty of Applied Physics and Mathematics Gdansk University of Technology Gdansk80-233 Poland Advanced Materials Center Gdansk University of Technology Gdansk80-233 Poland Materials Science and Technology Division Oak Ridge National Laboratory Oak RidgeTN37831 United States 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2024年

核心收录：

主　　题：Single crystals 

摘      要：The magnetic properties of EuAlSi, a compound comprising a honeycomb lattice of Al/Si atoms and a triangular lattice of Eu atoms, are presented. By means of single-crystal X-ray diffraction we find that EuAlSi crystallizes in a AlB2-type structure with space group P6/mmm and unit cell parameters a = 4.2229(10) Å, and c = 4.5268(12) Å. Our magnetic measurements indicate that EuAlSi is a soft ferromagnetic material with TCurie = 25.8 K. The susceptibility follows the Curie-Weiss law at high temperatures, which allowed us to determine the paramagnetic Curie temperature θP = 36.1 K and an effective magnetic moment µeff = 8.0 µB/Eu. This value is in agreement with the theoretical value of 7.9 µB for Eu2+ free ion. Moreover, we have prepared the Eu1-xSrxAlSi solid solution, where the atoms in the triangular lattice were systematically exchanged, in order to study the evolution of the collective quantum properties from the ferromagnetic EuAlSi towards the superconducting SrAlSi. Across the Eu1-xSrxAlSi solid solution the unit cell parameters change linearly, following Vegard’s law, suggesting that the changes in physical properties are more likely intrinsic, what makes the system reliable for studying composition dependence of the interplay between the crystal structure and physical properties. As the Sr content increases, i.e. x increases, we note a consistent reduction of µeff and TCurie. Long-range magnetic order in Eu1-xSrxAlSi persists up to x = 0.95, whereas superconductivity is only observed for samples with x 0.95. A possible quantum critical point is suggested to exist in the vicinity of to x ≈ 0.96, at which the suppression of ferromagnetic order is concomitant with the emergence of superconductivity. © 2024, CC BY.