Single crystal growths and magnetic properties of hexagonal polar semimetals RAuGe (R = Y, Gd-Tm, and Lu)
arXiv:2301.02794 · doi:10.1016/j.jallcom.2023.169475
Abstract
We study structural and magnetic properties of rare-earth based semimetals RAuGe (R = Y, Gd-Tm, and Lu) using flux-grown single crystals. These compounds belong to the noncentrosymmetric polar space group P63mc. We confirm the systematic structural evolution at room temperature as a function of ionic radius of rare earths to clarify the isopointal crossover between two polar structures: three-dimensional LiGaGe-type and quasi-two-dimensional NdPtSb-type. Magnetism shows a characteristic anisotropy in reasonable agreement with the crystal electric field (CEF) theory; the easy-plane-type anisotropy for R = Tb and Dy turns into the Ising-type anisotropy for R = Er and Tm. We evaluate the CEF parameters based on the Stevens operators to reasonably reproduce the temperature dependence of magnetic susceptibilities and specific heat for RAuGe (R = Tb-Tm). The estimated energy scale of the Ising gap (~ 11 meV) in TmAuGe is consistent with an excitation observed in an inelastic neutron scattering experiment. These findings suggest an opportunity for interplay between conduction electrons and nontrivial spin structures in the family of magnetic polar semimetals RAuGe.
10 pages, 7 figures, 1 table
References in corpus (7)
- 3D Dirac semimetals: current materials, design principles and predictions of new materials
- Spin Glass Order Induced by Dynamic Frustration
- Partial up-up-down order with the continuously distributed order parameter in the triangular antiferromagnet TmMgGaO4
- Polar Metals Taxonomy for Materials Classification and Discovery
- Noncentrosymmetric topological Dirac semimetals in three dimensions
- High electrical conductivity in the epitaxial polar metals LaAuGe and LaPtSb
- Influences of spin-orbit coupling on Fermi surfaces and Dirac cones in ferroelectric-like polar metals