Observation of a pressure-induced collapse of the Fe magnetic moment in the strong itinerant ferromagnetFe72Pt28

We observe a pressure-induced magnetic collapse from a ferromagnetic [high-moment, (HM)] state to a low-moment (LM) magnetic state in the strong itinerant ferromagnet ${\mathrm{Fe}}_{72}$ ${\mathrm{Pt}}_{28}$ (ordered and disordered phases). Such an existence of energetically closely lying HM and LM states demonstrates a unique physical picture of ferromagnetism in 3d magnetic systems that exhibit anomalously large magnetovolume effects. We further show that atomic ordering in ${\mathrm{Fe}}_{72}$ ${\mathrm{Pt}}_{28}$ stabilizes the ferromagnetic ground state against pressure and modifies the spin correlations of the pressure-induced LM magnetic ground state.