Spin Reorientation Transition Research Articles

Spontaneous Topological (Anti)meron Chains in the Domain Walls of Centrosymmetric Rare‐Earth Magnet

AbstractExploration and manipulation of topological protected magnetic swirls, such as skyrmion, antiskyrmion, meron, and vortex, holds significance for fundamental research and practical applications in high‐density magnetic information storage and spintronics because of their high storage density and low driven current. This study unveils the existence of field‐free spontaneous (anti)meron chains with a topological charge of ±1/2 in the centrosymmetric rare‐earth magnet Tb6Co2.17Si2.5 via in situ real‐space observation. The spin reorientation transition from in‐plane to uniaxial anisotropy contributes to the spontaneous transformation from straight domain walls to topological (anti)meron chains and to stripe domains along the [110] zone axis during in situ cooling. The study further confirms the critical role of the noncollinear magnetic structure of Tb atoms in the formation of topological (anti)meron chains via real‐space observations, first‐principles calculations, and micromagnetic simulations. The spontaneous topological magnetic texture is strongly correlated with the 4f electrons of rare‐earth atoms, enriching and stimulating alternative generation mechanisms of topological spin textures from emerging rare‐earth magnets, and further applications in spintronics.

Spin reorientation, spin switching, and magnetic compensation in Er1−xSmxFeO3 single crystals

We investigated spin reorientation, magnetic compensation and spin switching transitions in a series of high-quality single crystals of Er1−xSmxFeO3 (x = 0, 0.2, 0.4, 0.6, 0.8) prepared using the optical floating zone method. Structural and other preliminary characterizations confirmed the quality and phase purity of the crystals. Rietveld refinement of powder XRD data indicates that lattice parameters a and c increase linearly with increasing Sm concentration, whereas b remained constant. Field-cooled cooling (FCC) measurements revealed a temperature-induced spin reorientation transition (SRT) from Γ4 (Gx, Ay, Fz) to Γ2 (Fx, Cy, Gz) for all the samples. SRT temperature increased with Sm concentration and spread widely above and below room temperature. Moreover, magnetic compensation is common to all the compositions but decreases as Sm doping increases. We also observe type-I spin switching in samples with x = 0, 0.2, and 0.4 at an applied field of 60 Oe under FCC protocol, with a reduction in spin switching temperature as Sm content increased. For Sm-rich samples (x = 0.6, 0.8), spin switching was absent at 60 Oe.

Transfer of magnetic anisotropy in epitaxial Co/NiO/Fe trilayers

The magnetic properties of Co(10 Å)/NiO(40 Å)/Fe trilayer epitaxially grown on W(110) substrate were investigated with use of x-ray magnetic linear dichroism (XMLD) and x-ray magnetic circular dichroism (XMCD). We showed that magnetic anisotropy of Fe film that can be controlled by a thickness-driven spin reorientation transition is transferred via interfacial exchange coupling not only to NiO layer but further to ferromagnetic Co overlayer as well. Similarly, a temperature driven spin reorientation of Fe sublayer induces a reorientation of NiO spin orientation and simultaneous switching of the Co magnetization direction. Finally, by element specific XMCD and XMLD magnetic hysteresis loop measurements we proved that external magnetic field driven reorientation of Fe and Co magnetizations as well as NiO Néel vector are strictly correlated and magnetic anisotropy fields of Fe and Co sublayers are identical despite the different crystal structures.

Tailoring Magnetic Anisotropy in Ultrathin Cobalt by Surface Carbon Chemistry

AbstractThe ability to manipulate magnetic anisotropy is essential for magnetic sensing and storage tools. Surface carbon species offer cost‐effective alternatives to metal‐oxide and noble metal capping layers, inducing perpendicular magnetic anisotropy in ultrathin ferromagnetic films. Here, the different mechanisms by which the magnetism in a few‐layer‐thick Co thin film is modified upon adsorption of carbon monoxide (CO), dispersed carbon, and graphene are elucidated. Using X‐ray microscopy with chemical and magnetic sensitivity, the in‐plane to out‐of‐plane spin reorientation transition in cobalt is monitored during the accumulation of surface carbon up to the formation of graphene. Complementary magneto‐optical measurements show weak perpendicular magnetic anisotropy (PMA) at room temperature for dispersed carbon on Co, while graphene‐covered cobalt exhibits a significant out‐of‐plane coercive field. Density‐functional theory (DFT) calculations show that going from CO/Co to C/Co and to graphene/Co, the magnetocrystalline and magnetostatic anisotropies combined promote out‐of‐plane magnetization. Anisotropy energies weakly depend on carbidic species coverage. Instead, the evolution of the carbon chemical state from carbidic to graphitic is accompanied by an exponential increase in the characteristic domain size, controlled by the magnetic anisotropy energy. Beyond providing a basic understanding of the carbon‐ferromagnet interfaces, this study presents a sustainable approach to tailor magnetic anisotropy in ultrathin ferromagnetic films.

Spin reorientation transition in (110)-oriented NiCo2O4 epitaxial thin films

Magnetic anisotropy is an important character for magnetic materials. In this work, magnetic anisotropy of (110)-oriented ferrimagnetic NiCo2O4 (NCO) thin films deposited epitaxially on MgAl2O4 substrates by pulsed laser deposition is studied and compared with (001)-oriented NCO films. While the (001)-oriented films show a perpendicular magnetic anisotropy with the out-of-plane [001] direction as the magnetic easy axis, a jump in magnetic hysteresis loop is observed for the (110)-oriented films with a field applied vertically along the out-of-plane [110] direction. This jump in hysteresis loop is associated with a spin reorientation transition, depending on the applied field and temperature. Magnetic force microscopy reveals that this spin reorientation develops as domains nucleate, grow, and coalesce. This spin reorientation transition is discussed in terms of the competition between different magnetic anisotropy in an external field.

Low field controllable continuous spin switching in the thulium-ytterbium single crystal.

We report the spin reorientation transition (SRT) and the low field controllable continuous spin switching (SSW) of the Tm0.75Yb0.25FeO3 (TYFO) single crystal in this study. The SRT, characterized by the transition from Γ2(Fx, Cy, Gz)-Γ4(Gx, Ay, Fz), occurs within the temperature range of 20-27 K. Under an external magnetic field of 50 Oe, the SSW occurs along the c-axis at approximately 98 K due to the reversal of Tm3+ magnetic moment induced by the magnetic coupling change between Tm3+ and Fe3+, transitioning from a parallel to an antiparallel alignment. Notably, a continuous SSW is observed along the a-axis at low temperatures, which has not been previously reported in rare earth orthoferrites. This unique behavior can be easily manipulated by low magnetic fields within the temperature range of 2-20 K. Both the spin reorientation transition and spin switching phenomena in the TYFO single crystal arise from interactions between rare earth ions and iron ions and can be effectively regulated by applied low magnetic fields, making it a promising material for low-field spin devices.

Room-temperature spin reorientation transition and low-temperature significant magnetothermal effect in Mn-doped DyFeO3 single crystals

Rare-earth orthoferrites (RFeO3) promise in spin storage and spin sensing, but the majority of the magnetic phase transition and intriguing properties occur at low temperatures. Searching for higher-temperature or even room-temperature spintronics devices has been a critical challenge in the development of spintronics. We doped Mn ions into Fe sites of DyFeO3 in 10%–50 % ratios to coexist antiferromagnetic and ferromagnetic coupling in the ab plane and elevate their spin reorientation transition (SRT) temperatures. The structural, magnetic, and magnetothermal properties of the Mn-doped DyFeO3 single-crystal system are investigated. With increasing doping ratio, the Néel temperature progressively falls, while the SRT temperature (TSR) continuously rises to the room temperature of 307 K with a 40 % doping ratio, making it promising for room-temperature spin storage devices. When the ratio reaches 50 % (half doping), the magnetic configuration of Dy sublattices changes and a significant magnetothermal effect is observed. Because of low-field metamagnetic phase transition, the magnetic entropy change along the c-axis approaches 10.41 J/kg·K for the half doping crystal at 5 K (0 J/kg·K for DyFeO3, 0.93 J/kg·K for orthorhombic DyMnO3). The large adiabatic temperature change contributed by magnon indicates the exceptional refrigeration efficiency in a direct way. Therefore, it is possible to convert DyFeO3 into a room-temperature spin storage device material or a magnetic refrigeration contender at low temperatures.

Research progress in the magnetic domain wall topology

Topological magnetic skyrmions, as information units, possess distinct advantages such as high reliability, enhanced integration, and low energy consumption. These novel topological characteristics offer critical material and technological support for the rapid development of information technology, 5G communication, and big data. However, the application of magnetic skyrmions in practical devices is severely impeded by certain limitations, including their stability dependence on magnetic field and the deflection caused by the skyrmion Hall effect under electric current. Consequently, exploring new topological magnetic domain structures and material systems suitable for application becomes a pivotal area of research. This paper primarily focuses on experimental studies utilizing high-resolution Lorentz transmission electron microscopy for <i>in situ</i> real-space observation and manipulation of topological merons and skyrmions inside the magnetic domain wall, confirming the theoretical prediction of magnetic domain wall skyrmions in 2013. We has firstly achieved topological meron chains inside the domain walls by using the spin reorientation transition in two-dimensional van der Waals Fe<sub>5–<i>x</i></sub>GeTe<sub>2</sub> magnets, and systematically studied the dynamic behavior of domain wall topological magnetic domain structures under external electric and magnetic fields, filling the blanks in this research area. The important and special roles of magnetic domain walls are revealed at the same time. Then the GdFeCo amorphous ferrimagnetic thin film was designed and prepared based on the summarized mechanism with the domain wall meron pairs successfully reproduced. Moreover, the reversible topological transformation from domain wall meron pair to domain wall skyrmions has also been realized without external magnetic field during spin reorientation transformation as temperature changing. The results of micromagnetic simulation and electric experiments on the topological domains in domain walls would provided a strong basis and support for the future research.

Metamagnetic phase transition induced large magnetocaloric effect in a Dy0.5Ho0.5MnO3 single crystal.

Magnetic refrigeration based on the magnetocaloric effect is gaining interest in orthogonal or hexagonal rare-earth manganite. However, a more comprehensive understanding of the underlying mechanism is still required. We grew a high-quality single crystal of Dy0.5Ho0.5MnO3 using the optical floating zone method, since the parent crystals DyMnO3 and HoMnO3 have orthogonal and hexagonal structures, respectively. The magnetic and magnetocaloric properties and refrigeration mechanisms are thoroughly investigated. Doping modifies the magnetism according to the results obtained from the investigation of magnetic and dielectric properties and heat capacity. The spin reorientation transition shifts towards low temperature in comparison to HoMnO3. Near the Néel temperature of rare-earth sublattices (5 K), the highest changes in negative magnetic entropy under 0-70 kOe are 18 J kg-1 K-1 and 13 J kg-1 K-1 along the a- and c-axes, respectively. The low-temperature metamagnetic phase transition caused by the alterations in the magnetic symmetry of Ho3+ contributes to an increased magnetocaloric effect in comparison to the parent crystals, rendering it a promising choice for magnetic refrigeration applications. Dy0.5Ho0.5MnO3 exhibits a clear magnetocrystalline anisotropy with enhanced refrigeration capacity and negative magnetic entropy change along the a-axis. The adiabatic temperature change of Dy0.5Ho0.5MnO3 is 8.5 K, larger than that of HoMnO3, rendering it a promising choice for low-temperature magnetic refrigeration applications.

Study on the structure, Mössbauer and magnetic properties of polycrystalline Mn-doped SmFeO3

SmFe1−xMnxO3 (x = 0.0, 0.1, 0.3) polycrystalline powder samples were prepared by sol-gel method, and the obtained samples were all orthorhombic structures with Pbnm space group. Mössbauer spectroscopy at room temperature confirmed the +3 oxidation state of iron. All samples were fitted by sextet spectra, indicating that the samples are magnetically ordered at room temperature. The zero-field-cooled and field-cooled curves of SmFe0.9Mn0.1O3 sample show a reverse crossover trend at 5 K，and the magnetization is significantly enhanced after reaching the spin-switching transition temperature (Tssw∼285 K). SmFe0.7Mn0.3O3 sample exhibits a second-order spin-reorientation transition in the temperature range of 236–281 K. Rare-earth Sm ions underwent a spin-ordered transition from a paramagnetic state to an antiferromagnetic state at around 8 K. Due to the Dzyaloshinskii-Moriya antisymmetric interaction, the M − H curves of the sample at 5 K and 300 K both exhibit weak ferromagnetism.

Discovery of ultrafast spontaneous spin switching in an antiferromagnet by femtosecond noise correlation spectroscopy

Owing to their high magnon frequencies, antiferromagnets are key materials for future high-speed spintronics. Picosecond switching of antiferromagnetic spin systems has been viewed a milestone for decades and pursued only by using ultrafast external perturbations. Here, we show that picosecond spin switching occurs spontaneously due to thermal fluctuations in the antiferromagnetic orthoferrite Sm0.7Er0.3FeO3. By analysing the correlation between the pulse-to-pulse polarisation fluctuations of two femtosecond optical probes, we extract the autocorrelation of incoherent magnon fluctuations. We observe a strong enhancement of the magnon fluctuation amplitude and the coherence time around the critical temperature of the spin reorientation transition. The spectrum shows two distinct features, one corresponding to the quasi-ferromagnetic mode and another one which has not been previously reported in pump-probe experiments. Comparison to a stochastic spin dynamics simulation reveals this new mode as smoking gun of ultrafast spontaneous spin switching within the double-well anisotropy potential.

Effect of the surface anisotropy on the magnetic behavior of ultra-thin films single-domain on the spin reorientation transition regime by monte carlo simulation

In this work, Monte Carlo simulations allowed for studying the effect of the surface anisotropy on the Spin Reorientation Transition regime for single-domain ultra-thin films. The simulations included spin moments (1), exchange constant (10 meV), magnetocrystalline anisotropy (0.5 meV), and dipolar magnetic interaction (0.05 meV). We evaluated the surface anisotropy constant for K S = 0.5, 1, and 2 meV and thicknesses ranging from 3 to 11 cells. We determined the magnetothermal and hysteresis loop in- and out-plane at different angles to the plane. Analysis of Variance allows for modeling the coercivity as a function of the thickness and the applied field direction (in- and out-plane). Under these simulation conditions, the Spin Reorientation Transitions appear only at a thickness of 7 cells with K S =1 meV. The main contribution to magnetization rises out-plane at low thicknesses and in-plane at high values. However, the dominant magnetization contribution is in-plane for the thickness of 7 cells and low surface anisotropy. The magnetization is mainly oriented, out-plane for the high surface anisotropy case. However, hysteresis loops were observed independent of the applied magnetic field direction and thickness. Analysis of Variance results suggests that the thickness and the applied magnetic field direction allowed for tunning the coercivity (hard or soft magnetic materials). Sample simulated ignoring the magnetocrystalline and the surface anisotropies produce magnetic components in- and out-plane with slight differences as angle function. The combination of dipolar interactions and magnetocrystalline anisotropy showed two magnetic behaviors, a hard magnetic phase at low angles and a soft one at high angles in-plane direction. The inverse behavior results in the out-plane component. We observed the same behavior when surface anisotropy is considered. The differences are the transition angle of 50° in the first case and 30° in the second.

An abrupt spin reorientation transition and complex magnetic behavior in Dy0.7Nd0.3FeO3 single crystal

Discovery of novel functional materials is the cornerstone of spintronics and other emerging technologies. We report an abrupt spin reorientation transition from Γ4(Gx, Ay, Fz) to Γ2(Fx, Cy, Gz) in Dy0.7Nd0.3FeO3 single crystal that combines the Morin transition characteristics of DyFeO3 and the Γ2 spin configuration of NdFeO3. The Γ2 transition along a-axis has two critical temperatures corresponding to the rotation of Dy3+/Nd3+ spins and the spin reorientation of Fe3+ sublattice, respectively. At 5 kOe, the Γ4–Γ2 transition becomes a continuous one beginning at 27.3 K and the Γ4 spin configuration re-emerges at 7.8 K unexpectedly. The b-axis exhibits non-zero magnetization and Nd-related transition that disappear at 10 kOe at TSR due to a structural phase transition. The anomalous change in the mode frequencies and linewidth near the transition temperature observed in Raman spectroscopy reveals clear evidence of spin–phonon coupling in Dy0.7Nd0.3FeO3 single crystal.

Crystal structure, magnetic and Mössbauer studies of DyFexMn1-xO3 multiferroic manganites

The influence of iron replacement on the structural and magnetic properties of Dysprosium manganites was studied using the series of DyFexMn1-xO3 (x = 0.0, 0.1, 0.3, 0.5, 0.7, 0.9, and 1.0) compounds. All samples were fabricated by means of the modified auto-combustion sol-gel method, followed by the ball milling technique. Orthorhombic structure (Pnma space group) with high phase purity and crystallinity featured all samples, according to X-ray diffraction analysis. The temperature dependence of magnetization curves indicated antiferromagnetic (AFM) to paramagnetic (PM) transition with the increase in temperature. The Néel temperature (TN) was observed to shift to higher temperatures, whereas the spin reorientation transition temperature (TSR) reduced as Fe3+ content increased. Cusps in the zero-field-cooled (ZFC) curves were detected at low temperatures (around 4 K) as an indication of the ordering of the Dy spin. 57Fe Mӧssbauer spectra in samples with low iron content were dominated by a high spin (Fe3+) paramagnetic doublet at both 295 K and 78 K, while the distribution in the hyperfine magnetic field accounted for the appearance of the broadening magnetic peaks. High iron samples revealed a magnetic sextet with fit-resolved patterns that indicated a strong AFM coupling of Fe3+ ions. The hyperfine magnetic field (Bhf) magnitude demonstrated a linear increase with the increase in iron doping.

Temperature-driven magnetic and structural transitions in multiferroic Lu(1-x)ScxFeO3

Novel metastable hexagonal Lu(1-x)SxFeO3 compounds were prepared by an ethylene glycol-based small molecule sol-gel synthesis route. Samples were investigated by means of XRD, Raman spectroscopy, XPS, SEM and magnetometry techniques. Based on the obtained data several different phase composition regions were discovered at room temperature depending on the Sc content. Three dominant phases were observed and denoted as the orthorhombic Pnma, hexagonal P63cm, and cubic Ia-3 with the hexagonal phase being stable without any additional phases when 0.40 ≤ x < 0.65. Temperature dependent structural analysis allowed for the construction of the phase diagram which revealed that upon increasing Sc content the reversible polar to non-polar phase transition temperature can be decreased from above 1200 °C (when x = 0.15) to around 800 °C (x = 0.75). SEM analysis indicated a rapid reduction in particle size from ∼2.726 µm when x = 0 down to ∼0.962 µm when x = 0.75, however in the case when x = 1, an increase in particle size was observed. XPS analysis confirmed the elemental composition and its changes as well as the stability of the 3 + oxidation state of the iron ions. Magnetization measurements confirmed a non-zero room temperature magnetization as well as the spin reorientation transitions whose critical temperatures TN increases from 156 K (x = 0.25) to 170 K (x = 0.75).

Magnetism and Thermal Transport of Exchange-Spring-Coupled La2/3Sr1/3MnO3/La2MnCoO6 Superlattices with Perpendicular Magnetic Anisotropy.

Superlattices (SLs) comprising layers of a soft ferromagnetic metal La2/3Sr1/3MnO3 (LSMO) with in-plane (IP) magnetic easy axis and a hard ferromagnetic insulator La2MnCoO6 (LMCO, out-of-plane anisotropy) were grown on SrTiO3 (100)(STO) substrates by a metalorganic aerosol deposition technique. Exchange spring magnetic (ESM) behavior between LSMO and LMCO, manifested by a spin reorientation transition of the LSMO layers towards perpendicular magnetic anisotropy below TSR = 260 K, was observed. Further, 3ω measurements of the [(LMCO)9/(LSMO)9]11/STO(100) superlattices revealed extremely low values of the cross-plane thermal conductivity κ(300 K) = 0.32 Wm-1K-1. Additionally, the thermal conductivity shows a peculiar dependence on the applied IP magnetic field, either decreasing or increasing in accordance with the magnetic disorder induced by ESM. Furthermore, both positive and negative magnetoresistance were observed in the SL in the respective temperature regions due to the formation of 90°-Néel domain walls within the ESM, when applying IP magnetic fields. The results are discussed in the framework of electronic contribution to thermal conductivity originating from the LSMO layers.

High-pressure synthesis and magnetic properties of a Fe/Ru disordered quadruple perovskite CaCu3Fe2Ru2O12

A new quadruple perovskite oxide CaCu3Fe2Ru2O12 was synthesized at 10 GPa and 1400 K. The compound crystallizes into an AA′3B4O12-type perovskite structure with space group Im3¯, where the Ca and Cu ions are 1: 3 ordered at A sites, whereas Fe and Ru ions are disordered at B sites. X-ray photoelectron spectroscopy measurement reveals the charge state formation of CaCu2+3Fe3+2Ru5+2O12. Magnetic measurement shows that ferrimagnetic phase transition occurs at TC ∼348 K. Meanwhile, in a high applied magnetic field, a rapid decrease of zero-field-cooled magnetization MZFC occurs at low temperatures (TH), which may be due to spin-reorientation transition. When the applied pressure increases, TC moves to lower temperatures implying that ferrimagnetic exchange interaction becomes weak, while TH is almost unchanged. Electrical transport measurement shows that the intrinsic electrical behavior is metallic, which is consistent with the specific heat result.

Interwoven spin-reorientation and exchange bias in Nd1-xPrxCrO3

We report the systematic study of structural and magnetic properties of Nd1-xPrxCrO3 (0.0 ≤x≤ 0.30) perovskites. The XPS measurements confirm desired Pr (3+) valence state for the samples. The significant magnetization value with increased antiferromagnetic ordering (TN) and decreased spin-reorientation transition (TSR) is observed with Pr substitution. The enhanced weak ferromagnetism by Pr3+ presence dilutes Nd and Cr interactions, which finally vanishes TSR at maximum substitution. The Griffiths phase is observed in the substituted samples. A noticeable exchange bias (EB) effect is found for all samples. However, for the samples with higher Pr content, where spin-reorientation is suppressed, we observed the sharp increase in the EB field at 5 K (T < TSR). Interestingly, at 100 K (T > TSR), the substitution dependence of the EB field and magnetization link with the changes in the Cr-O bond length. Furthermore, the CrO6 octahedral Raman modes below TN mark spin-phonon coupling. The evolution of the magnetic phase diagram is given. The study sheds light on tuned spin-reorientation, EB effect, and structural features in Nd1-xPrxCrO3 compounds.

Tunable magnetic phase transition in thulium–samarium orthoferrite single crystals

Spintronics and condensed matter physics are in pursuit of materials that can serve as carriers for novel quantum devices. Antiferromagnetic rare earth orthoferrites (RFeO3, where R is rare earth or Y), are potential functional materials for magnetic information processing. They exhibit temperature-controlled spin reorientation transition (SRT) and magnetic field/temperature-induced spin switching (SSW) properties. As such, RFeO3 is expected to be used in spintronic devices that can easily control the spin. With the advancement of research, the co-doping of rare earth ions has emerged as a prominent area of investigation in RFeO3. In this work, we have grown a series of Tm1-xSmxFeO3 (TSFO, x = 0, 0.2, 0.3, 0.4) single crystals via a four-mirror optical floating zone furnace. Crystal axes and single phase of these single crystals were determined using Laue back reflection camera and X-ray diffractometer. We observed that the doping of Sm ions can effectively regulate the spin reorientation temperature of the parent material TmFeO3. Both type-I and type-II SSW have been observed when the doping rate x is 0.2 or 0.4, perfectly integrating the magnetic properties of TmFeO3 and SmFeO3 single crystals. Furthermore, the spin switching in TSFO (x = 0.2, 0.3, 0.4) can be manipulated by applying low magnetic fields with tens of Oe. On the other hand, when the doping rate x reaches 0.4, the magnetic compensation phenomenon and the Néer temperature of rare earth ions occurred. The super-exchange interaction between R3+ and Fe3+ magnetic sublattices leads to these interesting phenomena.

Size and density control of skyrmions with picometer CoFeB thickness variations—observation of zero-field skyrmions and skyrmion merging

The controlled formation and adjustment of size and density of magnetic skyrmions in Ta/CoFeB/MgO trilayers with low Dzyaloshinskii–Moriya interaction is demonstrated. Close to the out-of-plane to in-plane magnetic spin reorientation transition, we find that small energy contributions enable skyrmion formation in a narrow window of 20 pm in CoFeB thickness. Zero-field stable skyrmions are established with proper magnetic field initialization within a 10 pm CoFeB thickness range. Using magneto-optical imaging with quantitative image processing, variations in skyrmion distribution and diameter are analyzed quantitatively, the latter for sizes well below the optical resolution limit. We demonstrate the controlled merging of individual skyrmions. The overall demonstrated degree of comprehension of skyrmion control aids to the development of envisioned skyrmion based magnetic memory devices.