Abstract:
The antiphase domain structure in the Ni$_3$Mn alloy with superstructure $L1_2$ with various manganese contents has been studied. It has been found that a deviation of the alloy composition from the stoichiometry leads to the formation of manganese oxides at the antiphase domain boundaries and grain boundaries. With an increase in the antiphase domain sizes, the domain size distribution function changes from the normal to lognormal, and the degree of long-range atomic order decreases.