Zero-Field Skyrmions Generated Via Premartensitic Transition In Ni50mn35.2in14.8 Alloy

Magnetic phase transition contributes to magnetocaloric effects and magnetoelastic coupling, producing significant multifunctions in Ni-based Heusler alloys. In this paper, the peculiar intermediate premartensitic phase during the transition from parent phase to martensite is identified in Ga-free Ni50Mn35.2In14.8 alloy via Lorentz transmission electron microscopy combined with in situ magnetizing and cooling manipulation. The simultaneous coexistence of three skyrmion configurations at zero field in martensite is directly observed with correlation to the appearance of the intermediate magnetic phase and martensite twinning confinement. The evolution of magnetic domains demonstrates a mechanism to generate skyrmions with magnetization orientation adjusted via magnetic phase transition, which illustrates the associated physical properties.