Such boundaries were observed in monocrystalline films that had been grown onto MgO. The antiphase boundaries were an intrinsic result of film nucleation and growth. The intra sub-lattice super-exchange coupling was greatly strengthened across an antiphase boundary, while the inter sub-lattice super-exchange coupling was weakened; thus reversing the predominant interaction found in the bulk. The antiphase boundaries thus separated oppositely magnetized regions; consistent with Lorentz microscopy measurements. The antiphase boundaries introduced very large saturation fields and almost random magnetization distributions in zero field.

D.T.Margulies, F.T.Parker, M.L.Rudee, F.E.Spada, J.N.Chapman, P.R.Aitchison, A.E.Berkowitz: Physical Review Letters, 1997, 79[25], 5162-5