Metastable skyrmion phase stabilized in wider T–H region of β-Mn type Co7Zn7Mn6 chiral magnet

Abstract

We report the evolution of magnetic phase diagram (), by accounting for the successive magnetic phase transitions in β-Mn-type Co7Zn7Mn6, a chiral magnet by an elaborate AC susceptibility magnetometry, χ(T, H). The phase diagram of polycrystalline Co7Zn7Mn6 helimagnet reveals two distinct equilibrium skyrmion phases driven by fluctuations; conventional skyrmion phase (SkX) with helical ordering just below ∼ 215 K and disordered skyrmion phase (DSkX) just above spin-glass region. The topological nature of SkX is due to high () spins moment and magnetic disorder driven weak pinning effect manifesting into the stabilization of robust meta-stable skyrmion phase (MSkX) by trivial field-cooling via SkX at = 110 K and 150 K. We performed first-principles based density functional theory based calculations, which corroborate with the experimental structural and magnetic ground state of skyrmion-host Co7Zn7Mn6 chiral magnet.