Magnetostriction, piezomagnetism and domain nucleation in a kagome antiferromagnet

Abstract

Whenever the elastic energy of a solid depends on magnetic field, there is a magnetostrictive response. Field-linear magnetostriction implies piezomagnetism and vice versa. Here, we show that Mn${}_3$Sn, a non-collinear antiferromanget with Weyl nodes, hosts a large and almost perfectly linear magnetostriction even at room temperature. The longitudinal and transverse magnetostriction, with opposite signs and similar amplitude are restricted to the kagome planes and the out-of-plane response is negligibly small. By studying four different samples with different Mn:Sn ratios, we find a clear correlation between the linear magnetostriction, the spontaneous magnetization and the concentration of Sn vacancies. The recently reported piezomagnetic data fits in our picture. We show that linear magnetostriction and piezomagnetism are both driven by the field-induced in-plane twist of spins. A quantitative account of the experimental data requires the distortion of the spin texture by Sn vacancies. We find that the field-induced domain nucleation within the hysteresis loop corresponds to a phase transition. Within the hysteresis loop, a concomitant mesoscopic modulation of local strain and spin twist angles, leading to twisto-magnetic stripes, arises as a result of the competition between elastic and magnetic energies.

12 pages, 7 figures, Supplementary Materials included

References in corpus (11)

• Electrical Manipulation of a Topological Antiferromagnetic State
• Topological Weyl semimetals in the chiral antiferromagnetic materials Mn3Ge and Mn3Sn
• Non-collinear Antiferromagnets and the Anomalous Hall Effect
• Cluster multipole theory for anomalous Hall effect in antiferromagnets
• Piezomagnetic switching of anomalous Hall effect in an antiferromagnet at room temperature
• Chiral domain walls of Mn${}_3$Sn and their memory
• Thermodynamic evidence for valley-dependent density of states in bulk bismuth
• Giant effective damping of octupole oscillation in an antiferromagnetic Weyl semimetal
• Anisotropic magnetic interactions in hexagonal AB-stacked kagome lattice structures: Applications to ${\mathrm{Mn}}_3\mathrm{X}$ ($\mathrm{X}$ = $\mathrm{Ge}$, $\mathrm{Sn}$, $\mathrm{Ga}$) compounds
• Strong Magneto-Elastic Coupling in Mn${}_3$X (X = Ge, Sn)
• The free energy of twisting spins in Mn${}_3$Sn

Cited by in corpus (7)

• Anisotropic Piezomagnetism in Noncollinear Antiferromagnets
• Piezomagnetism in the Ising ferromagnet URhGe
• Manipulation of magnetic systems by quantized surface acoustic wave via piezomagnetic effect
• Saturated and Anisotropic Magnetostriction in an Altermagnet
• Strain-induced manipulation of non-collinear antiferromagnets
• Efficient spin-pumping and spin transport across epitaxial Mn${}_3$Sn(0001) noncollinear antiferromagnet/permalloy interfaces
• High-Field Terahertz Spin Resonance in Cr${}_2$O${}_3$ above the Spin-Flop Transition