Physical pressure and chemical expansion effects on the skyrmion phase in Cu₂OSeO₃

Chopping skyrmions from magnetic chiral domains with uniaxial stress in magnetic nanowire

“…On the other hand, strain has been used to manipulate magnetic domains in soft magnetostrictive materials [30][31][32][33][34][35]. Recent, experiments have demonstrated that mechanical strain or stress are effective means to control the skyrmion phase [36][37][38]. In this letter, we will show that it is possible to cut a skyrmion from a chiral stripe domain (CSD) by applying an in-plane uniaxial strain.…”

Anisotropy-induced depinning in the Zn-substituted skyrmion host Cu2OSeO3

“…One way to control the relative contribution of these energy terms is by varying the elemental composition of skyrmion-hosting materials via chemical substitution or doping. Compositional effects have been studied in a range of systems, such as Fe 1−x Co x Si [34][35][36], Mn 1−x (Fe/Co) x Si [37][38][39][40], Mn 1−x Fe x Ge [41][42][43][44], MnSi 1−x Ge x [45], Co 10−x Zn 10−y Mn x+y [16,22,23,46], Co 8−x (Fe/Ni/Ru) x Zn 8 Mn 4 [47], GaV 4 (S 8−x Se x ) [48,49], [Cu 1−x (Zn/Ni) x ] 2 OSeO 3 [50][51][52][53][54][55], and Cu 2 OSe 1−x Te x O 3 [56]. The properties altered include variation of T c , indicating a change in the exchange interaction strength; alteration of the magnitude and sign of the DMI, leading to changes in the helical and skyrmion lattice periodicity and chirality; switching of the magnetic easy axes, and therefore the helical ground-state domain orientation, by tuning of the cubic anisotropy constants; and modification of the spin wave propagation.…”

Room-temperature skyrmion phase in bulk Cu 2 OSeO 3 under high pressures

“…Cu 2 OSeO 3 | skyrmion | helimagnet | topological | high pressure I n a noncentrosymmetric helimagnetic compound, the complex competitions among the various magnetic interactions in decreasing strengths, that is, the exchange interaction, the Dzyaloshinskii-Moriya (DM) spin-orbit interaction, and the crystalline anisotropy, result in a generic but complex magnetic field (H)-temperature (T) phase diagram. For instance, on cooling to below the magnetic transition temperature T c , Cu 2 OSeO 3 undergoes a paramagnetic-to-helical magnetic transition in a low H less than ∼0.5 kOe but a paramagnetic-to-conical magnetic transition in an intermediate H below ∼2 kOe and a paramagnetic-toferrimagnetic transition in a large H above ∼2 kOe (1)(2)(3)(4). In this generic H-T phase diagram, the skyrmion phase occurs in a very restricted region near T c ∼58 K, as depicted schematically in Fig.…”

“…1. Magnetic skyrmions on the scale of approximately tens of nanometers emerge with vortex-like spin textures and form the skyrmion lattice state, which has been detected by means of smallangle neutron scattering (SANS) (2, 5), resonant elastic X-ray scattering (6,7), Lorentz force transmission electron microscopy (LTEM) (1,8,9), magnetic force microscopy (10,11), electron holography (12), optical polarization rotation measurements (13), and magnetization measurements (1,3,4,14,15). As a result, great potential has been envisioned for skyrmions for high-density information storage, ultrafast spintronics, and efficient microwave devices (16,17).…”