Magnetic ground state dependent magnetostriction effects on the chiral magnet CrNb3S6

Abstract

A prototype of the monoaxial chiral magnet ${\mathrm{CrNb}}_{3}{\mathrm{S}}_{6}$ exhibited two magnetostriction (MS) effects: (1) spontaneous MS due to the exchange interaction and spin-orbit coupling (SOC) at zero dc magnetic field ($H$) [Phys. Rev. B 102, 014446 (2020)] and (2) paramagnetic MS due to SOC and Zeeman energy at room temperature [Phys. Rev. B 105, 104412 (2022)]. ${\mathrm{CrNb}}_{3}{\mathrm{S}}_{6}$ has various magnetic structures, such as helimagnetic, first chiral soliton lattice (CSL-1), second CSL (CSL-2), CSL-2 with irreversibility, and forced ferromagnetic phases, resulting from the Dzyaloshinskii--Moriya interaction as a function of $H$ below the magnetic ordering temperature (${T}_{\mathrm{c}}$). In this study, we conducted powder x-ray diffraction analyses to investigate the effects of $H$ and temperature ($T$) on the MS at the atomic level. The $T$ dependence of the lattice constants reveals that below ${T}_{\mathrm{c}}$, the MS depends on the magnetic structure. The MS below ${T}_{\mathrm{c}}$ is discussed in this study in terms of both the hybridization between the ${z}^{2}$ orbital of $\mathrm{Nb}(4f)$ and delocalized ${a}_{1}$ orbital of Cr and the structural symmetry of the ${\mathrm{CrS}}_{6}$ octahedron.