arXiv subjects

I. N. Khoroshiy

Publications and source records attributed to I. N. Khoroshiy.

3 recordsLinked to original sources

arXiv2026

Anisotropy of spin waves in the field-polarized phase of Fe-doped MnSi

Chiral magnetic textures, such as skyrmions, are of great interest to the condensed matter community due to their novel transport properties. The stabilization of topologically non-trivial magnetic phases, like the skyrmion lattice in cubic MnSi, is governed by underlying magnetic interactions which can be probed via measurements of spin-wave excitations. Here, we report high-resolution inelastic neutron scattering (INS) measurements of the spin waves in Fe-doped Mn$_{0.9}$Fe$_{0.1}$Si deep within its field-polarized ferromagnetic state. We observe non-reciprocal spin waves with a parabolic dispersion that shifts linearly with magnetic field. Crucially, the spin-wave stiffness is highly anisotropic, with values of 17.2(5) meV~$\rm{\mathring{A}}$$^2$ parallel to the applied field and 9.3(3) meV~$\rm{\mathring{A}}$$^2$ perpendicular to it. While the applied field fundamentally lowers the systems symmetry from cubic to uniaxial, we demonstrate that the induced spin-wave anisotropy is significantly large, which is not captured within the simple theoretical approximations widely applied up to date.

cond-mat.str-el↗

arXiv2026

Effect of Magnetic Vacancies on the Spontaneous Spin-Reorientation Transition in HoFe$_{1-x}$Al$_x$O$_3$ Single Crystals

In this work, we report the first growth of single crystals of the substitution series HoFe$_{1-x}$Al$_x$O$_3$ with aluminium concentrations up to $x=0.2$ and investigate the evolution of their spontaneous spin-reorientation transition (SRT). Among rare-earth orthoferrites, HoFeO$_3$ exhibits a distinctive sequence of magnetic phases ($Γ_4$-$Γ_{24}$-$Γ_{12}$-$Γ_2$). This complex sequence arises from the competition between the $K_{ac}$ and $K_{ab}$ anisotropies associated with the Ho$^{3+}$ ions and the effective magnetic field produced by the weak ferromagnetic moment of the canted Fe$^{3+}$ sublattice. Introducing magnetic vacancies perturbs the antiferromagnetic compensation of the Fe$^{3+}$ subsystem in the $ab$ plane and generates an additional effective magnetic field acting on the Ho$^{3+}$ ions. This field alters the balance between the $K_{ac}$ and $K_{ab}$ anisotropies within the SRT temperature range and thereby broadens the stability range of the $Γ_{12}$ phase in the magnetic phase diagram.

cond-mat.mtrl-sci↗

arXiv2025

First-Order Spin-Reorientation Transition and Incomplete Softening of the Antiferromagnetic Resonance Mode in Multiferroic GdFe$_3$(BO$_3$)$_4$

The multiferroic ferroborate GdFe$_3$(BO$_3$)$_4$ with huntite-type structure exhibits magnetic ordering below T$_N$ = 38 K and contains two magnetic subsystems associated with Gd and Fe ions. Competing anisotropies of these subsystems drive a spin reorientation transition at T$_{SR}$ = 10.7 K, switching the ground state from easy-axis to easy-plane. Using antiferromagnetic resonance, we investigate the spin dynamics across this transition. The observed incomplete softening of a magnon mode during both field- and temperature-induced spin-reorientation transitions indicates the first-order nature of the phase transition, which is accompanied by a discontinuous jump in the effective anisotropy field. We reproduce this behavior using a simple model that attributes the jump in the anisotropy field to the presence of an effective fourth-order anisotropy constant, responsible for the discontinuous character of the transition. Remarkably, for in-plane magnetic fields, we identify a new AFMR mode that persists from 12 K up to T$_N$. This mode likely corresponds to the dynamics of a long period incommensurate state, previously detected by resonant elastic X-ray scattering.

cond-mat.str-el↗