Magnetic skyrmions, topologically protected chiral spin textures having potential applications in data storage, are stabilized in certain magnetic materials with broken inversion symmetry. The existence of magnetic antiskyrmions has been recently demonstrated in thin plates of a tetragonal Heusler material with D 2d crystal symmetry. Here, the robust nature of the antiskyrmion phase in bulk tetragonal Mn-Pt(Pd)-Sn compounds by utilizing magnetic entropy change and AC-susceptibility measurements is shown. It is found that the formation of the antiskyrmion phase is accompanied by a positive magnetic entropy change, which is supported by the concomitant observation of an anomaly in AC-susceptibility measurements. Supporting these findings, no anomalies are found in AC-susceptibility and magnetic entropy change measurements for a Mn-Pt(Pd)-Sn compound that is stabilized in the cubic phase by slight changes in chemical composition, thereby showing the robustness of the antiskyrmion phase to the D 2d crystal structure.

The successful realization of skyrmion-based spintronic devices depends on the easy manipulation of underlying magnetic interactions in the skyrmion-hosting materials. Although the mechanism of skyrmion formation in non-centrosymmetric magnets is comprehensively established, the stabilization process of different skyrmion-like magnetic textures in centrosymmetric magnets needs further investigation. Here, we utilize Lorentz transmission electron microscopy study to report the finding of a tunable skyrmion lattice up to room temperature in a centrosymmetric kagome ferromagnet Mn4Ga2Sn. We demonstrate that a controlled switching between the topological skyrmions and non-topological type-II magnetic bubbles can be realized at the optimal magnetic anisotropy. We find that the topological skyrmions are the energetically most stable magnetic objects in the centrosymmetric hexagonal magnets, whereas application of in-plane magnetic field stabilizes type-II magnetic bubbles as an excited state. The present study is a significant step towards understanding of the skyrmion stabilization mechanism in centrosymmetric materials for their future applications.

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