Giant magnetic coercivity and ionic superlattice nano-domains in Fe_0.25TaS₂

Abstract

We have explored giant magnetic coercivity (Hc≈7 tesla) in the highly anisotropic ferromagnet of Fe0.25TaS2 through harnessing order of Fe2+ ions intercalated in-between TaS2 layers. Fe ions order well in annealed crystals and form a (1/2,0,0) superlattice. However, a (1/3,1/3,0) superlattice, in addition to the (1/2,0,0) superlattice, can form in quenched crystals. These coexisting superlattices with nano-size domains result in significant change of magnetic domain configurations and huge enhancement of Hc, probably through efficient magnetic domain wall pinning by nano-size superlattice domains.