Magnetization measurements and computer simulations for the magnetic hysteresis losses of reentrant ${\mathrm{Ni}}_{100\mathrm{-}\mathit{x}}$${\mathrm{Mn}}_{\mathit{x}}$Pt and Ni-Mn alloys

We have carried out ac and dc magnetization measurements on ${\mathrm{Ni}}_{74}$ ${\mathrm{Mn}}_{24}$ ${\mathrm{Pt}}_2$ alloy in the temperature range of 4.2–300 K. When 2 at. % platinum impurity atoms are substituted in place of nickel atoms, it has been observed that both the unidirectional and uniaxial anisotropies are significantly induced, while the freezing temperature (${\mathit{T}}_{\mathit{f}}$) remains nearly unchanged within experimental uncertainty. In addition, the unusually large magnetic hysteresis losses (broadening loops) observed for this alloy have been attributed to the induced unidirectional anisotropy rotation and to the increase of the uniaxial anisotropy. In order to justify the assertion mentioned above, we have also introduced a simple model based on Kouvel’s model by taking into account the elastic anisotropy rotation and the uniaxial anisotropy component.