Suppression of ferromagnetism within antiphase boundaries in Ni50Mn25Al12.5Ga12.5 alloy

This paper reports on the unexpectedly narrow magnetic domain walls observed at the positions of antiphase boundaries (APB) in a system of ferromagnetic shape memory alloys Ni50Mn25Al12.5Ga12.5. Lorentz microscopy observations determined the wall width at the APB position to be 12 nm, which is substantially smaller than the width at the APB-free position of 48 nm. This result can be explained by the modulation of magnetic parameters near APB, within which ferromagnetism is suppressed by the deterioration of Heusler-type ordering.